LIBRARY UNIV6RSITY OF CALIFORNIA SAN DIEGO LIBRARY UNIVERSITY OF CALIFORNIA SAN DIEGO 7 V The Dragon-fly (Libellula defressa). A. Perfect Insect. B. Perfect Insect emerging from the Pupa. c. D. Larvae and Pupa;. THE INSECT WORLD: A Popular Acwint of the Orders of Insects ; TOGETHER WITH A DESCRIPTION OF THE HABITS AND ECONOMY OF SOME OF THE MOST INTERESTING SPECIES. LOUIS FIGUIER. REVISED AND CORRECTED BY P. MARTIN DUNCAN, F.R.S. WITH 579 ILLUSTRATIONS. D. APPLETON AND CO., NEW YORK, PREFACE. THIS popular French book on Insects has been placed in my hands in order that the scientific portions of it should be examined and, if necessary, corrected. This task has been a light one, for the book had already passed through the able editorship of Mr. Jansen. But I have added a short notice of the Thysanoptera, which did not appear in M. Figuier's original work, and also the necessary informa- tion respecting the evolution of Stylops. P. MARTIN DUNCAN. LEE, 1872. CONTENTS, PAGE INTRODUCTION f f APTERA DIPTERA Nemocera ..... ,c Brachycera .... HEMIPTERA Heteroptera Homopi era IOI LEPIDOPTERA g The Larva, or Caterpillar r ,g The Chrysalis, or Pupa I4 g The Perfect Insect l6 - ORTHOPTERA HYMENOPTERA THYSANOPTERA NEUROPTERA 402 COLEOPTERA . 523 THE INSECT WORLD. INTRODUCTION. IT is not intended to investigate the anatomy of insects in this work thoroughly ; but, as we are about to treat of the habits and economy of certain created beings, it is necessary first to explain the principal parts of their structure, and the stages which every perfect insect or imago has undergone before arriving at that state. We, therefore, proceed to explain, as simply as possible, the anatomy of an insect, and the functions of its organs. If we take an insect, and turn it over, and examine it carefully, the first thing that strikes us is that it is divided into three parts : the head ; the thorax, or chest ; and the abdomen, or stomach. The head (Fig. i) is a kind of box, formed of a single piece, having here and there joints more or less strongly marked, sometimes scarcely visible. It is furnished in front with an opening often very small which is the mouth ; and with some for the eyes, and with others for the insertion of the antennas or horns. The integuments of the head are generally harder than the other parts of the body. It is necessary that this should be so. Insects often live and die in the midst of substances which offer some resistance. It is necessary, therefore, that the head should be strong enough to overcome such resistance. The head contains the masticatory organs, which, frequently having to attack hard substances, must be strongly sup- ported. The exception to this rule is among insects which live by suction. It would be out of place here to mention the numerous modifi- Fig. i. Head of an Insect. 2 THE INSECT WORLD. cations of the head which are presented in the immense class of insects. The eyes of insects are of two kinds. There are compound eyes, or eyes composed of many lenses, united by their margins and forming hexagonal facettes ; and there are also simple eyes, or ocelli. The exterior of the eye is called the cornea (Fig. 2), each facette being a cornea ; and the facettes, which vary in size even in the same eye, unite and form a common r, g .2.-A compound Cornea. cornea> wh i ch is represented by the entire figure. In order to show the immense number of the facettes possessed by many insects, we give the following list : In the genus Mordella (a genus of beetles) the eye has 25,008 facettes. In the Libellula (dragon-fly) 12,544 In the genus Papilio (a genus of butterflies) . . 17,355 In Sphinx convolvuli (the convolvulus hawk -moth) . 1,300 In Bftnbyx mori (the common silkwonn moth) . 6,236 In the house-fly 4,000 In the ant 50 In the cockchafer 8,820 The facettes appear to be most numerous in insects of the genus Scarabceus (a genus of beetles). They are so minute, that they can only be detected with a magnifying glass. Looked at in front, a compound eye may be considered an agglomeration of simple eyes ; but internally this is hardly correct. On the under side of each facette we find a body of a gelatinous appearance, transparent, and usually conical; the base of this occupies the centre of the facette in such a manner as to leave around it a ring to receive some colouring matter. This body diminishes in thickness towards its other extremity, and terminates in a point where it joins a nervous filament proceeding from the optic nerve. These cones, agreeing in number with the facettes, play the part of the crystalline lens in the eyes of animals. They are straight and parallel with each other. A pigment fills all the spaces between the cones, and between the nervous filaments, and covers the under side of each cornea, except at the centre. This pigment varies much in colour. There are almost always two layers, of which the exterior one is the more brilliant. In fact, these eyes often sparkle with fire, like precious stones. INTRODUCTION. 3 M. Lacordaire, in his " Introduction a 1'Entomologie," from which we borrow the greater part of this information, has summed up as follows, the manner in which, according to M. Miiller, the visual organs of insects operate : " Each facette, with its lens and nervous filament, separated from those surrounding them by the pigment in which they are enclosed, form an isolated apparatus, impenetrable to all rays of light, except those which fall perpendicularly on the centre of the facette, which alone is devoid of pigment. All rays falling obliquely are absorbed by that pigment which surrounds the gelatinous cone. It results partly from this, and partly from the immobility of the eye, that the field of vision of each facette is very limited, and that there are as many objects reflected on the optic filaments as there are cornese. The extent, then, of the field of vision will be determined, not by the diameter of these last, but by the diameter of the entire eye, and will be in proportion to its size and convexity. But what- ever may be the size of the eyes, like their fields of vision, they are independent of each other ; there is always a space, greater or less, between them; and the insect cannot see objects in front of this space without turning its head. What a peculiar sensation must result from the multiplicity of images on the optic filaments ! This is not more easily explained than that which happens with animals which, having two eyes, see only one image ; and probably the same is the case with insects. But these eyes usually look in opposite directions, and should see two images, as in the chameleon, whose eyes move independently of each other. The clearness and length of vision will depend, continues M. Miiller, on the diameter of the sphere of which the entire eye forms a segment, on the number and size of the fa'cettes, and the length of the cones or lenses. The larger each facette, taken separately, and the more brilliant the pigment placed between the lenses, the more distinct will be the image of objects at a distance, and the less distinct that of objects near. With the latter the luminous rays diverge considerably; while those from the former are more parallel. In the first case, in traversing the pigment, they impinge obliquely on the crystalline, and consequently confuse the vision; in the second, they fall more perpendicularly on each facette. " Objects do not appear of the same size to each optic filament, unless the eye is a perfect section of a sphere, and its convexity concentric with that of the optic nerve. Whenever it is otherwise, the image corresponds more or less imperfectly with the size of the object, and is more or less incorrect. Hence it follows, that 4 THE INSECT WORLD. elliptical or conical eyes, which one generally finds among insects, are less perfect than those referred to above. "The differences which exist in the organisation of the eye among insects are explicable, to a certain point, on the theory which we are about to explain in a few words. Those species which live in the same substances on which they feed, and those which are parasitical, have small and flattened eyes ; those, on the contrary, which have to seek their food, and which need to see objects at a distance, have large or very convex eyes. For the same reason the males, which have to seek their females, have larger eyes than the latter. The position of the eyes depends also on their size and shape; those which are flat, and have consequently a short field of vision, are placed close together, and rather in front than at the sides of the head, and often adjoining. Spherical and convex eyes, on the contrary, are placed on the sides, and their axes are opposite. But the greater field of vision which they are able to take in makes up for this position." Almost all insects are provided with a pair of compound eyes, which are placed on the sides of the head. The size and form of these organs are very variable, as we shall presently see. They are generally placed behind the antennce. Although simple eyes (ocelli or stemmata) are common, they do not exist in all the orders of insects. They are generally round, and more or less convex and black, and there are three in the majority of cases. When there is this number they are most frequently placed in a triangle behind, and at a greater or less distance from the antennae. Under the cornea, which varies in convexity, is found a transparent, rather hard, and nearly globular body, which is the true crystalline resting on a mass, which represents the vitreous body. This vitreous body is enclosed in an expansion of the optic nerve. Besides these, there is a pigment, most frequently red-brown, sometimes black, or blood-red. The organisation of these eyes is analogous to the eyes of fishes, and their refractive power is very great. With these eyes insects can only see such objects as are at a short distance. Of what use then can stemmata be to insects also provided with compound eyes ? It has been remarked that most insects having this arrangement of eyes feed on the pollen of plants, and it has been surmised that the stemmata enable them to distinguish the parts of the flowers. The antennas, commonly called horns, are two flexible appendages, of very variable form, which are joined to different parts of the head, and are always two in number. The joints of which they are made INTRODUCTION. up have the power of motion, which enables the insect to move them in any direction. The antennae consist of three parts : the basal joint, commonly distinguished by its form, length, and colour ; the club, formed by a gradual or sudden thickening of the terminal joints, of which the number, form, and size present great variations ; lastly, the stalk, formed by all the joints of the antennae, except the basal, when no club exists, and in case of the existence of a club, of all those between it and the basal one. We give as examples the antennae of two beetles, one of the genus Asida, the other of the genus Zygia (Figs. 3 and 4). Insects, for the most part, while in repose, place their antennae on their backs, or along the sides of the head, or even on the thorax. Others are provided with cavities in which the antennae repose either wholly or in part. During their different movements, insects move their antennae more or less, sometimes slowly and with regu- larity, at other times in all directions. Some insects impart to their antennae a perpetual vibration. During flight they are directed in front, perpendicular to the axis of the body, or else they repose on the back. What is the use of the antennae, resembling as they do, feathers, saws, clubs, &c. ? Everything indicates that these organs play a very important part in the life of insects, but their functions are imperfectly understood. Experience has shown that they only play a subordinate part as feelers, and have nothing to do with the senses of taste or smell. There is no other function for them to fulfil, except that of hearing. On this hypothesis the antennae will be the principal instruments for the transmission of sound-waves. The membrane at their base represents a trace of the tympanum which exists among the higher animals. This membrane then will have some connection with an auditory nerve. The mouth of insects is formed after two general types, which correspond to two kinds of requirements. It is suited in the one case to break solid substances, in the other to imbibe liquids. 6 THE INSECT WORLD. At first sight there seems no similarity between the mouth of a biting insect and of one living by suction. But on examination it is found that the parts of the mouth in the one are exactly analogous to the same parts in the other, and that they have only modifications suiting them to the different purposes which they have to fulfil. The mouth of a biting insect is composed of an upper lip, a pair of mandibles, a pair of jaws, and a lower lip (Fig. 5). The lower lip and the jaws carry on the outside certain appendages or filaments which have received the name of palpi. When speaking of sucking insects, and in general of the various Fig. 5. Mouth of a masticating insect. Fig. 6. Thorax of Acrocinus longimanus (a beetle). orders of insects, we shall speak more in detail of the various parts or the mouth. The thorax (Fig. 6), the second primary division of the body of insects, plays almost as important a part as the head. It consists of three segments or rings, which are in general joined together the prothorax, the mesothorax, and the metathorax, each of which bears a pair of legs. The wings are attached to the two posterior segments. All insects have six true legs. There is no exception whatever to this rule, though some may not be developed. From the segments to which they are attached, the legs are called anterior, posterior, and intermediate. The legs are composed of four parts : the trochanter, a short joint which unites the thigh to the body ; the thigh or femur ; the tibia, answering to the shank in animals ; and the tarsus, or foot, composed of a variable number of pieces placed end to end, and called the phalanges. We take as examples the hind leg of a Heterocerus (Fig. 7), and the front leg ofiZcptosis (Fig. 8) (genera of beetles). IN TROD UCTION. We shall not dwell on the different parts, as they perform functions which will occupy us later, when speaking of the various species of the great class of insects. The functions which the legs of insects have to perform con- sist in walking, swimming, or jumping. In walking, says M. Lacor daire, insects move their legs in different ways. Some move their six legs successively, or only two or three at a time without dis- tinction, but never both legs of the same pair together, conse- quently one step is not the same as another. The walk of insects is sometimes very irregular, espe- cially when the legs are long ; and they often hop rather than walk. Others have one kind of step, and walk very regularly. They commence by moving the pos- terior and anterior legs on the same side and the intermediate ones on the opposite side. The first step made, these legs are put down, and the others raised in their turn to make a second. Running does not change the order of the movements, it only makes them quicker very rapid in some species, and surpassing in proportion that of all other animals; but in others the pace is Slow. Some insects rather Fig. 9. Posterior leg of a jumping insect. crawl than walk. In swimming, the posterior legs play the principal part. The other legs striking the water upwards or downwards, produce an upward or downward motion. The animal changes its course at will by using the legs on one side only, in the same way as one turns a rowing boat with one oar without the aid of a rudder. Swim- ming differs essentially from walking, for the foot being surrounded 8 THE INSECT WORLD. by a resisting medium, the legs on both sides are moved at the same time. The act of jumping is principally performed by the hind legs. Insects which jump have these legs very largely developed, as in Fig. 9. When about to jump they bring the tibia into contact with the thigh, which is often furnished with a groove to receive it, having on each side a row of spines. The leg then suddenly straightens like a spring, and the foot being placed firmly on the ground, sends the insect into the air, and at the same time propels forward. The jump is greater in proportion as the leg is longer. To treat here in a general manner of the wings of insects would be useless. We shall refer to them at length in their proper place, when treating of the various types of winged insects. In the perfect insect the abdomen does not carry either the wings or the legs. It is formed of nine segments, which are without ap- pendages, with the exception of the posterior ones, which often carry small organs differing much in form and function. These are saws, probes, forceps, stings, augers, &c. We shall consider these different organs in their proper places. With vertebrate animals, which have an interior skeleton suited to furnish points of resistance for their various movements, the skin is a more or less soft covering, uniformly diffused over the exterior of the body, and intended only to protect it against external injury. In insects the points of resistance are changed from the interior to the exterior. The skin is altered by Nature to fit it to this purpose. It is hard, and presents between the segments only membranous intervals, which allow the hard parts to move in all directions. We are examining a perfect insect ; we have glanced at its skele- ton, and the different appendages which spring from it. The prin- cipal organs which are contained in the body remain to be examined. We will first study the digestive apparatus. This apparatus con- sists of a lengthened tubular organ, swollen at certain points, forming more or less numerous convolutions, and provided with two distinct orifices. This alimentary canal is always situated in the median line of the body, traverses its whole length, and is at first surrounded by, and then passes above, the nervous ganglia.* In its most complicated form the alimentary canal is composed of an oesophagus, or gullet, of a crop, of a gizzard, of a chylific ven- tricle or stomach, a small intestine, a large intestine, divers appendages, salivary, biliary, and urinary glands. The oesophagus is often not * Ganglion a mass, literally a knot, of nervous matter. INTRODUCTION. wider than a hair, and part of it in many species is enlarged into a pouch, which is called the crop, because it occupies the same position, and performs analogous functions with that organ in birds. It is enough to say that the food remains there some time before passing on to the other parts of the intestinal canal, and undergoes a certain amount of preparation. It is in the gizzard, when one exists, that the food, separated by the masticatory organs of the mouth, undergoes another and more complete grinding. Its structure is suited to its office. It is, in fact, very muscular, often half cartilaginous, and strongly contractile. Its in- terior walls are provided with a grinding apparatus, which varies according to the species, and consists of teeth, plates, spines, and notches, which convert the food into pulp. It only exists among insects which live on solid matters, hard vegetables, small animals, tough skin, &c. This apparatus is absent in sucking insects and those which live on soft substances, such as the pollen of flowers, &c. The chylific ventricle or stomach is never absent; it is the organ which performs the principal part in the act of digestion. Two kinds of appendages belong to the chylific ventricle, but only in certain families. The first are papilla?, in the form of the fingers of a glove, which bristle over the exterior of this organ, and in which it is believed that the food begins to be converted into chyle. The second are casca, and larger and less numerous. They have been considered as secretory organs, answering to the pancreas in vertebrate animals. Fig. io. Digestive apparatus of Carabus auratus. 10 THE INSECT WORLD. Fig. 10, which represents the digestive apparatus of Carabus aurattts, a common beetle, presents to the eyes of the reader the different organs of which we are speaking. A is the mouth of the insect, B the oesophagus, c the crop, D the gizzard, E the chylific ventricle, F and G the small and large intestines, and H the anus. It is not necessary to consider the other parts of the alimentary canal in insects, but only to refer to some of the appendages of this apparatus. The salivary glands pour into the di- gestive tube a liquid, generally colourless, which, from the place where it is secreted, and its alkaline nature, corresponds to the saliva in vertebrate animals. It is this liquid which comes from the tongue of sucking insects in the form of drops. These glands are always two in number. Their form is as variable as complicated. The most simple is that of a closed flexible tube, generally rolled into a ball, and open- ing on the sides of the oesophagus. At the posterior extremity of the chylific ventricle are inserted a variable number of fine tubes, usually elongated and flexible, and terminating in culs-dc-sac at one end. Their colour, which depends on the liquid they may contain, is sometimes white, but more frequently brown, blackish, or green. They appear to be composed of a very slight and delicate membrane, as they are very easily torn, and nothing is more diffi- cult than to unroll and to disengage them from the fatty or other tissues by which they are enveloped. The function of these vessels is uncer- tain. Cuvier and Leon Dufour supposed them to be analogous to the liver, and on that account they have been called biliary vessels ; and they are often termed the Malpighian vessels, after the name of their discoverer. According to M. Lacordaire, their functions vary with their Fig. ii. Posterior extremity of the chylific ventricle, surrounded by the Malpighian vessels. INTRODUCTION. II position. When they enter the chylific ventricle, they furnish only bile; bile and a urinary liquid when they enter the posterior part of the ventricle and the intestine ; and urine alone when they are placed near the posterior extremity of the alimentary canal. Fig. ii represents part of the preceding figure more highly magnified, showing the manner in which these tubes enter the chylific ventricle. In our rapid description of the digestive apparatus of insects, it only remains for us to mention cer- tain purifying organs which secrete those fluids, generally blackish, caustic, or of peculiar smell, which some insects emit when they are irritated, and which cause a smarting when they get into one's eyes. Less well developed than the salivary organs, they are often of a very complicated structure. In Fig. 1 2 is represented the secretory apparatus of the Carabns anratus, which will serve for an example : A represents the secretory sacs aggregated together like a bunch of grapes, B the canal, c the pouch which receives the secretion, D the excretory duct. Sometimes the secretion is liquid, and has a foetid or am- moniacal odour; sometimes, as in the Bombardier beetle (Brachinns crepitans}, it is gaseous, and is emitted, with an explosion, in the form of a whitish vapour, having a strong pungent odour analogous to that of nitric acid, and the same properties. It reddens litmus paper, and burns and reddens the skin, which after a time becomes brown, and continues so for a considerable time. About the middle of the seventeenth century Malpighi at Bologna, and Swammerdam at Utrecht, discovered a pulsatory organ occupying a median line of the back, which appeared t& them to be a heart, in different insects. Nevertheless, Cuvier,. having declared some time afterwards that there was no circula- Fig. 12. Secretory apparatus of Carabus auratus. 12 THE INSECT WORLD. tion, properly so called, among insects, his opinion was universally adopted. But in 1827 a German naturalist named Cams discovered that there were real currents of blood circulating throughout the body, and returning to their point of departure. The observations of Cams were repeated and confirmed by many other naturalists, and we are thus enabled to form a sufficiently exact idea of the manner in which the blood circulates. The following summary of the phenomena of circulation among insects is borrowed from " Lecons sur la Physiologic et 1'Anatomie compare'e," by M. Milne-Edwards : The tube which passes under the skin of the back of the head, and front part of the body, above the alimentary canal, has been known for a long time as the dorsal vessel. It is composed of two very distinct portions : the anterior, which is tubular and not con- tractile ; and the posterior, which is larger, of more complicated structure, and which contracts and dilates at regular intervals. This latter part constitutes, then, more particularly the heart of the insect. Generally it occupies the whole length of the abdomen, and is , fixed to the vault of the tegumentary skeleton by membranous expansions, in such a manner as to leave a free space around it, but shut above and below, so as to form a reservoir into which the blood pours before penetrating to the heart. This reservoir is often called the auricle, for it seems to act as an instrument of impulsion, and to drive the blood into the ventricle or heart, properly so called. The heart is fusiform, and is divided by numerous constrictions into chambers. These chambers have exits placed in pairs, and membranous folds which divide the cavity in the manner of a portcullis. The lips of the orifices, instead of terminating in a clean edge, penetrate into the interior of the heart in the form of the mouth-piece of a flute. The double membranous folds thus formed on each side of the dorsal vessel are in the shape of a half moon, and separate from each other when this organ dilates ; but the contrary movement taking place, the passage is closed. By the aid of this valvular apparatus, the blood can penetrate into the heart from the pericardic chamber, the empty space surrounding the heart, but cannot flow back from the heart into that reservoir. The anterior or aortic portion of the dorsal vessels shows neither fan-shaped lateral expansions, nor orifices, and consists of a single membranous tube. The whole of the blood set in motion by the contractions of the cardial portion of the dorsal vessel runs into the cavity of the head, and circulates afterwards in irregular channels INTROD UCTION. 1 3 formed by the empty spaces left between the different organs. It is the unoccupied portions of the great visceral cavity which serve as channels for the blood, and through them run the main currents to the lateral and lower parts of the body. These currents regain the back part of the abdomen, and enter the heart after having passed over the internal organs. These principal channels are in continuity with other gaps between the muscles, or between the bundles of fibres of which these muscles are composed. The principal currents send into the network thus formed, minor branches, which having ramified in their turn among the principal parts of the organism, re-enter some main current to regain the dorsal vessel. In the transparent parts of the body the blood may be seen circulating in this way to a number of inter-organic channels, pene- trating the limbs and the wings, when these appendages are not horny, and, in short, diffusing itself everywhere. " If, by means of coloured injections," says M. Milne-Edwards, " one studies the connections which exist between the cavities in which sanguineous currents have been found to exist and the rest of the economy, it is easy to see that the irrigatory system thus formed penetrates to the full depth of every organ, and should cause the rapid renewal of the nourishing fluid in all the parts where the process of vitality renders the passage of this fluid necessary." We shall see presently, in speaking of respiration, that the relations between the nourishing fluid and the atmospheric air are more direct and regular than was for a long time supposed. In short, insects possess an active circulation, although we find neither arteries nor veins, and although the blood put in motion by the contractions of the heart, and carried to the head by the aortic portion of the dorsal vessel, can only distribute itself in the different parts of the system to return to the heart, by the gaps left between the different organs, or between the membranes and fibres of which these organs are composed. Fig. 13 (page 14), which shows both the circulating and breathing systems of an insect, enables us to recognise the different organs which we have described, as helping to keep up both respiration and circulation. The knowledge of the respiration of the insect is comparatively a modern scientific acquisition. Malpighi was the first to prove, in 1669, that insects are provided with organs of respiration, and that air is as indispensable to them as it is to other living beings. But the opinion of this celebrated naturalist has been contradicted, and his THE INSECT WOKLD. Fig. 13. Organs of circulation and breathing in an insect. A, abclominnl portion of the dorsal vessel. , aortic or thoracic ; ortion. c, air-vessels of the head ; D, of the abdomen. INTRODUCTION. 15 views were long contested. Now, however, one can easily recognise the apparatus by the aid of which the respiration of the insect is effected. The respiratory apparatus is essentially composed of membranous ducts of great tenuity, their ramifications spread everywhere in incalculable numbers, and bury themselves in the different organs, much in the same way as the fibrous roots of plants bury themselves in the soil. These vessels are called tracheae. Their communications with the air are established externally in different ways, according to the character of the medium in which the insect lives. It is well known that a vast number of insects live in the air. The air penetrates into the tracheae by a number of orifices placed at the sides of the body, which are termed spiracles. On close examination these may be seen in the shape of button-holes in a number of different species. Let us dwell for a moment on the breathing apparatus of the insect, that is to say, on the tracheae. This apparatus is sometimes composed of elastic tubes only, some- times of a collection of tubes and membranous pouches. We will first treat of the former. The coats of these breathing tubes are very elastic, and always preserve a cylindrical form, even when not distended. This state of things is maintained by the existence, throughout the whole length ot the tracheae, of a thread of half horny consistency, rolled up in a spiral, and covered externally by a very delicate membranous sheath. The external membrane is thin, smooth, and generally colourless, or of a .pearly white. The cartilaginous spiral is sometimes cylindrical and sometimes flat. It only adheres slightly to the external mem- brane, but is, on the other hand, closely united to the internal one. This spiral thread is only continuous in the same trunk ; it breaks off when it branches, and each branch then possesses its own thread, in such a way that it is not joined to the thread of the trunk from which it issued, except by continuity, just as the branch of a tree is attached to the stem which supports it. This thread is prolonged, without interruption, to the extreme points of the finest ramifications. The number of tracheae in the body of an insect is very great. That patient anatomist, Lyonet, has proved this in his great work on the Goat-moth Caterpillar, Cossi/s ligniperda. Lyonet, who con- gratulated himself with having finished his long labours without having had to destroy more than eight or nine of the species he wished to describe, had the patience to count the different air-tubes in that caterpillar. He found that there were 256 longitudinal and 1 6 THE INSECT WORLD. 1,336 transverse branches ; in short, that the body of this creature is traversed in all directions by 1,572 aeriferous tubes which are visible to the eye by the aid of a magnifying glass, without taking into account those which may be imperceptible. The complicated system of the breathing apparatus which we are describing is sometimes composed of an assemblage of tubes and membranous pouches, besides the elastic tubes which we have already mentioned. These pouches vary in size, and are very elastic, expanding when the air enters, and contracting when it leaves them, as they are altogether without the species of framework formed by the spiral thread of the tubular tracheae, of which they are only enlargements. Fig. 13 is explanatory of these organs of respiration. The respiratory mechanism of an insect is easily understood. " The abdominal cavity," says M. Milne-Edwards, " in which is placed the greater part of the respiratory apparatus, is susceptible of being contracted and dilated alternately by the play of the different segments of which the skeleton is composed, and which are placed in such a manner that they can be drawn into each other to a greater or less extent. When the insect contracts its body, the tracheae are compressed and the air driven out. But when,, on the other hand, the visceral cavity assumes its normal size,, or dilates, these channels become larger, and the air with which they are filled being rarefied by this expansion, is no longer irt equilibrium with the outer air with which it is in communication through the medium of the spiracles. The exterior air is then impelled into the interior of the respiratory tubes, and the inspiration is effected." The respiratory movements can be accelerated or diminished, according to the wants of the animal ; in general, there are from thirty to fifty to the minute. In a state of repose the spiracles are open, and all the tracheae are free to receive air whenever the visceral cavity is dilated, but those orifices may be closed, and the insect thus possesses the faculty of stopping all commu- nication between the respiratory apparatus and the surrounding atmosphere. Some insects live in the water; they are therefore obliged to come to the surface to take the air they are in need of, or else to possess themselves of the small amount contained in the water. Both these methods of respiration exist under different forms in aquatic insects. To inhale atmospheric air, which is necessary for respiration, INTRODUCTION. above the water, certain insects employ their elytra* as a sort of reservoir; others make use of their antennae, the hairs of which retain the globules of air. In this case it is brought under the thorax, whence a groove carries it to the spiracles. Some- times the same result is obtained by a more complicated arrangement, con- sisting of respiratory tubes which can be thrust into the air, which it is their func- tion to introduce into the organisation. Insects which breathe in the water without rising to the surface are provided with gills organs which, though variable in form, generally consist of foliaceous or fringed expansions, in the midst of which the tracheae ramify in considerable numbers. These vessels are filled with air, but it does not disseminate itself in them directly, and it is only through the walls of these tubes that the contained gas is exchanged for the air held in sus- pension by the surrounding water. The oxygen contained in the water passes through certain very permeable mem- branes of the gill, and penetrates the tracheae, which discharge, in exchange, carbonic acid, which is the gaseous pro- duct of respiration. Fig. 14 represents the gills or breathing .apparatus in an aquatic insect. We take as an example EpJiemera.\ It may be observed that the gills or foliaceous laminae are placed at the circumference of the body, and at its smallest parts. We have now seen that the respiratory apparatus is considerably developed in insects ; it is, therefore, easy to foresee that those functions are most actively employed by them. In fact, * The homy upper wings with which some insects are provided are called elytra. ED. t May-fly family. ED. Fig. 14. Branchiae, or gills, of an aquatic larva - (Ephemera). A, foliaceous laminae, or gills. 1 8 THE INSECT WORLD. if one compares the oxygen they imbibe with the heavy organic matter of which their body is composed, the amount is enormous. Before finishing this rapid examination of the body of an insect, we shall have to say a few words on the nervous system. This system is chiefly composed of a double series of ganglions, or collections of nerves, which are united together by longitudinal cords. The number of these ganglions corresponds with that of the segments. Sometimes they are at equal distances, and extend in a chain from one end of the body to the other ; at others they are many of them close together, so as to form a single mass. The cephalic ganglions are two in number ; they have been described by anatomists under the name of brain. " This expres- sion," says M. Lacordaire, "would be apt to mislead the reader, as it would induce him to suppose the existence of a concentration of faculties to control the feelings and excite the movements, which is not the case."* The same naturalist observes, "All the ganglions of the ventral chain are endowed with nearly the same properties, and represent each other uniformly." The ganglion situated above the oesophagus gives rise to the optic nerves, which are the most considerable of all those of the body, and to the nerves of the antennae. The ganglion beneath the oesophagus provides the nerves of the mandibles, of the jaws, and of the lower lip. The three pairs of ganglions which follow those placed immediately below the oesophagus, belong to the three segments of the thorax, and give rise to the nerves of the feet and wings. They are in general more voluminous than the following pairs, which occupy the abdomen. Fig. 15 represents the nervous system of the Carabus auratus: A is the cephalic ganglion ; B, the sub-oesophagian ganglion ; c, the prothoracic ganglion ; D and E are the ganglions of the mesothorax and metathorax. The remainder, F F, are the abdominal ganglions. Before finishing these preliminary observations, it is necessary to say that the preceding remarks only apply absolutely to insects arrived at the perfect state. It is important to make this remark, as insects, before arriving at that state, pass through various other stages. These stages are often so different from each other, that it would be difficult to imagine that they are only modifications of the same animal ; one would suppose that they were as many different kinds of animals, if there was not abundant proof of the contrary. * "Introduction 4 1'Entomologie," tome il p. 192. 8vo. Paris. 1838. INTRODUCTION. 19 The successive stages through which an insect passes are four Fig. 15. Nervous system of Carabus auratus. in number : the egg ; the larva ; the pupa, nymph, or chrysalis ; and the perfect insect, or imago. c 2 2O THE INSECT WORLD. The egg state, which is common to them, as to all other articu- late animals, it is unnecessary to explain. Nearly all insects lay eggs, though some few are viviparous. There often exists in the extremity of the abdomen of the female a peculiar organ, called the ovipositor, which is destined to make holes for the reception of the eggs. By a wonderful instinct the mother always lays her eggs in a place where her young, on being hatched, can find an abundance of nutritious substances. It will not be needless to observe that in most cases, these aliments are quite different to those which the mother seeks for herself. In the second stage, that is to say, on leaving the egg the larva period the insect presents itself in a soft state, without wings, and resembles a worm. In ordinary language, it is nearly always called a worm, or grub, and in certain cases, a caterpillar. Linnaeus was the first to use the term " larva " taken from the Latin word larva, " a mask " as he considered that, in this form, the insect was as it were masked. During this period of its life the insect eats voraciously, and often changes its skin. At a certain period it ceases to eat, retires to some hidden spot, and, after changing its skin for the last time, enters the third stage of its existence, and becomes a chrysalis. In this state it resembles a mummy enveloped in bandages, or a child in its swaddling clothes. It is generally incapable of either moving or nourishing itself. It continues so for days, weeks, months, and sometimes even for years. While the insect is thus apparently dead, a slow but certain change is going on in the interior of its body. A marvellous work, though not visible outside, is being effected, for the different organs of the insect are developing by degrees under the covering which surrounds them. When their formation is complete, the insect disengages itself from the narrow prison in which it was enclosed, and makes its appearance, provided with wings, and capable of propagating its kind ; in short, of enjoying all the faculties which Nature has accorded to its species. It has thrown off the mask ; the larva and pupa has dis- appeared, and given place to the perfect insect. To show the reader the four states through which the insect passes in succession, in Fig. 16 is represented the insect known as the Hydrophilus* firstly, in the egg state ; secondly, as the larva, or caterpillar ; thirdly in the pupa ; and fourthly as the perfect insect or imago. The different degrees of transformation and evolution which we have just described, are those which take place either completely * A kind of water-beetle. ED. INTRODUCTION, 21 or incompletely in all insects. Their metamorphoses are then at an end. There are certain insects, however, that show no difference in their various stages, except by absence of wings in the larva ; and in these the chrysalis is only characterised by the growth of the wings, which, at first folded back and hidden under the skin, afterwards become free, but are not wholly developed till the last skin is cast. These insects are said to undergo incomplete metamorphoses, the Fig. 16. Hydrophilus in its four states. A, eggs ; B, larva ; C, pupa ; D, imago, or perfect insect. former complete metamorphoses. Some never possess wings ; indeed, there are others which undergo no metamorphosis, and are born pos- sessed of all the organs with which it is necessary they should be provided. Some curious researches have been lately made on the strength of insects. M. Felix Plateau, of Brussels, has published some observations on this point, which we think of sufficient interest to reproduce here. 22 THE INSECT WORLD. In order to measure the muscular strength of man, or of animals as the horse, for instance many different dynamometric apparatuses have been invented, composed of springs, or systems of unequal levers. The Turks' heads which are seen at fairs, or in the Champs Elyse'es, at Paris, and on which the person who wishes to try his strength gives a strong blow with his fist, represent a dynamometer of this kind. The one which Buffon had constructed by Regnier the mechanician, and which is known by the name of Regnier' s Dynamo- meter, is much more precise. It consists of an oval spring, of which the two ends approach each other ; when they are pulled in opposite directions, a needle, which works on a dial marked with figures, indicates the force exercised on the spring. It has been proved, with this instrument, that the muscular effort of a man pulling with both hands is about 124 Ibs., and that of a woman only 74 Ibs. The ordinary effort of strength of a man in lifting a weight is 292 Ibs. ; and a horse, in pulling, shows a strength of 675 Ibs.; a man, under the same circumstances, exhibiting a strength of 90 Ibs. Physiologists have not has yet given their attention to the strength of invertebrate animals. It is, relatively speaking, immense. Many people have observed how out of proportion a jump of a flea is to its size. A flea is not more than an eighth of an inch in length, and it jumps a yard ; in proportion, a lion ought to jump two-thirds of a mile. Pliny shows, in his " Natural History," that the weights carried by ants appear exceedingly great when they are compared with the size of these indefatigable labourers. The strength of these insects is still more striking, when one considers the edifices they are able to construct, and the devastations they occasion. The Termes, or White Ant,* constructs habitations many yards in height, which are so firmly and solidly, built, that the buffaloes are able to mount them, and use them as observatories ; they are made of particles of wood joined together by a gummy substance, and are able to resist even the force of a hurricane. There is another circumstance which is worth being noted. Man is proud of his works ; but what are they, after all, in comparison with those of the ant, taking the relative heights into consideration ? The largest pyramid in Egypt is only 146 yards high, that is, about ninety times the average height of man ; whereas, the nests of the Termites are a thousand times the height of the insects which construct them. Their habitations are thus twelve times higher than the largest specimen of architecture raised by human hands. We are, therefore, * A neuropterous insect, not a true ant. ED. INTRODUCTION. 2$ far beneath these little insects, as far as strength and the spirit of working go. The destructive power of these creatures, so insignificant in appearance, are still more surprising. During the spring of a single year they can effect the ruin of a house by destroying the beams and planks. The town of La Rochelle, to which the Termites were imported by an American ship, is menaced with being eventually suspended on catacombs, like the town of Valencia in New Grenada. It is well known what destruction is caused when a swarm of locusts alight in a cultivated field ; and it is certain that even their larvae do as severe injury as the perfect insect. All this sufficiently proves the destructive capabilities of these little animals, which we are accus- tomed to despise. M. Plateau has studied the power of traction in some insects, the power of pushing in the digging insects, and the lifting power of others during flight. He has thus been able to make some most interesting comparisons, of some of which we will relate the results. The average weight of man being 142 Ibs., and his power of traction, according to Regnier, being 124 Ibs., the proportion of the weight he can draw to the weight of his body is only as 87 to 100. With the horse the proportion is not more than 67 to 100, a horse I 535 Ibs. in weight only drawing about 900 Ibs. The horse, there- fore, can draw little more than half his own weight, and a man cannot draw the weight of his own body. This is a very poor result, if compared with the strength of the cockchafer. This insect, in fact, possesses a power of traction equal to more than fourteen times its own weight. If you amuse yourself with the children's game of making a cockchafer draw small cargoes of stones, you will be surprised at the great weight which this insigni- ficant looking animal is able to manage. To test the power of traction in insects, M. Plateau attached them to a weight by means of a thread fastened to one of their feet. The Coleoftera (Beetles) are the best adapted for these experiments. The following are some of the results obtained by the Belgian physician : Carabtis auratus can draw seven times the weight of its body ; Nebria brevicollis, twenty-five times ; Necrophorus vespillo, fifteen times ; Trichius fasciatus, forty-one times ; and Oryctes nasi- cornis, four times only. The bee can _ draw twenty times the weight of its body ; Donacia nymphw* forty-two times its own weight. * A beetle. -ED. 24 THE INSECT WORLD. From this it follows that if the horse possessed the same strength as this last insect, or if the insect were the size of a horse, they would either of them be able to draw 155,250 Ibs. M. Plateau has ascertained the pushing power in insects, by introducing them into a pasteboard tube, the interior of which was made rough, and in which was fixed a glass plate, which allowed the light to penetrate into the prison. The animal, if excited, struggled with all its strength against ' the transparent plate, which, on being pushed forward, turned a lever adapted to a miniature dynamometer, which indicated the amount of effort exercised. The results thus obtained prove that the pushing power, like the power of traction, is greater in inverse proportion to the size and weight of the animal. A few figures will better explain this curious law. In Oryctes nasicornis the proportion of the pushing power to the weight of the insect is only three to two ; in Geotrupes sterco- rarius it is sixteen to two ; and in Onthophagus nuchicornis seventy- nine to six. Experiments have been made on the lifting power of insects by fastening a ball of soft wax to a thread attached to the hind legs. The proportion of the weight lifted has been found equal to that of the body. That is to say, that the insect, when flying, can lift its own weight. This is proved by the following calculations : In the Neuroptera the proportion is i in the Dragon-fly (Libellula vulgata\ 7 in Lestes sponsa. In the order Hymenoptera it is 78 in the bee, and '63 in Bombus terrestris, the humble-bee. In the Diptera it is 9 in Calliphora vomitoria* 1*84 in the Syrphus corolla, and 177 in the house-fly. These results show that insects have only sufficient power to sustain their own weight when flying, as the above calculations exhibit the maximum of which they are capable, and at the utmost this strength would only compensate for the fatigue occasioned by the action of flight. At the same time it is to be observed that the Diptera, and among others the house-fly, can sustain their flight longer than the Hymenoptera and Neuroptera, although one would not think so from their appearance. In conclusion, if an insect's power of flying is not considerable, its power of traction and propulsion are immense, compared with the vertebrate animals ; and, in the same group of insects, those that are the smallest and lightest are the strongest. The proportion between the muscular strength of insects and the * The meat-fly. ED. INTRODUCTION. 2$ dimensions of their bodies, would not appear to be on account of their muscles being more numerous than those of vertebrate animals, but on account of greater intrinsic energy and muscular activity. The articulations of insects may be considered as solid cases which envelop the muscles, and the thickness of these cases appears to decrease in a singular manner according to the size of the creature. The relative bulk of the muscles being less in the smaller species than in the larger, it is necessary to explain the superior relative strength of the former by supposing them to possess a greater amount of vital energy. These astonishing phenomena will perhaps be better understood if we consider the obstacles which insects have to overcome to satisfy their wants, to seek their food, to defend themselves against their enemies, &c. To meet these requirements they are marvellously constructed for both labour and warfare, and their strength is superior to that dis- played by all other animals. It is also much greater than that of the machines we construct to replace manual labour. They represent strength itself. God's workmen are infinitely more powerful than those invented by the genius of man, which we call machines. We think it necessary, in closing this chapter, to give a sort of general outline of the great class of animals which we are about to study. If we wished to characterise insects by their exterior aspect, we might consider them as articulate animals, whose bodies, covered with tough and membranous integuments, are divided into three distinct parts : the head, provided with two antennae, and eyes and mouth of very variable form ; a trunk or thorax, composed of three segments, which has underneath it always six articulated limbs, and often above it two or four wings ; and an abdomen, composed of nine segments, although some may not appear to exist at first sight. If, in addition to these characteristics, one considers that these animals are not provided with interior skeletons that their nervous system is formed of a double cord, swelling at intervals, and placed along the underside of the body, with the exception of the first swellings or ganglions which are under the head that they are not provided with a complete circulating system that they breathe by particular organs, termed tracheae, extending parallel to each other along each side of the body, and communicating with the exterior air by lateral openings termed spiracles that their sexes are distinct that they are reproduced from eggs and, in conclusion, that the different parts we have mentioned are not complete until the creature has passed through several successive changes, called metamorphoses. 26 THE INSECT WORLD. a general idea may be formed of what is meant in zoology by the word "insect." Insects, whose general organisation we have briefly traced, have been classed by naturalists as follows : 1. APTERA (Fleas and Lice). 2. DIPTERA (Gnats, Flies, &c.) 3. HEMIPTERA (Bugs, &c.) 4. LEPIDOPTERA (Butterflies and Moths). 5. ORTHOPTERA (Grasshoppers, Crickets, Cockroaches, &c.) 6. HYMENOPTERA (Bees, Wasps, &c.) 7. THYSANOPTERA ( Thrips cereaiium). 8. NEUROPTERA (Libellula, or Dragon-fly ; Ephemera, or May-fly ; Phryganea, or Alder -fly). 9 . COLEOPTERA (Beetles). We shall commence the history of the various orders by examin- ing the Aptera. APTERA. INSECTS of this order are without wings, and the name is derived from two Greek words, a , privative, and irr f pbv, wing, indicating the negative character which constitutes this order.* It consists of Fleas and Lice. The Flea (Pulex), of which De Geer formed a separate group, and called Suctoria, includes several species. The common flea (Pulex irritans, Fig. 17) has a body of oval form, somewhat flattened, covered with a rather hard horny skin of a brilliant chestnut brown colour. It is the breaking of this hard skin which produces the little crack which is heard when, after a successful hunt, one has the happiness to crush one of these parasites between one's nails. Its head, small in proportion to the body, is compressed, and carries two small antennae, Flea ( Pul of cylindrical form, composed of four joints, which the animal shakes continually when in motion, but which it lowers and rests in front of its head when in a state of repose. The eyes are simple, large, and round. The beak is composed of an exterior jointed sheath, having inside it a tube, and carrying under- neath two long sharp lancets, with cutting and saw-like edges. It is with this instrument that the flea pierces the skin, irritates it, and causes the blood on which it lives to flow. This bite, as every one knows, is easily recognised by the presence of small darkish red spots, surrounded by a circle of a paler colour. * It is probable that one day the order Aptera will be superseded. The absence of wings is not really a character of great value. De Blainville, Mollard, Pouchet, Van Beneden, and Gervais, have made several attempts in that direction. The fleas have been placed among the Diptera, and the lice among Hemiptera in the " Traite de Zoologie Medicale " of these two last authors. 28 THE INSECT WORLD. The quantity of blood absorbed by this little creature is enormous, when compared with its size. The body of the flea is divided into thirteen segments* of which one forms the head; three the thorax, which is short, and the remainder the abdomen. The limbs are long, strong, and spiny. The tarsus or foot, has five joints, and terminates in hooks turned in opposite directions. The two anterior limbs are separated from the others, and are inserted nearly under the head ; the posterior ones are particularly large and strong. The jumps which fleas are able to make are really gigantic, and the strength of these little animals quite herculean, when compared with the size of their bodies. The reader may be inclined to smile at the assertion that the flea possesses herculean strength ; but let him wait a little, and he will find that it is no exaggeration. To give some idea of the strength, the docility, and the goodwill of the fleas, some wonderful little things have been made, which have served at the same time to show the astonishing skill of certain workmen. In his " Histoire abrege'e des Insectes," published in the seventh year of the French Republic, Geoffroy relates that a certain Mark, an Englishman, had succeeded, by dint of patience and art, in making a gold chain the length of a finger, with a padlock and a key to fasten it, not exceeding a single grain in weight. A flea attached to the chain pulled it easily. The same learned writer relates a still more surprising fact. An English workman constructed a carriage and six horses of ivory. The coachman was on the box, with a dog between his legs, there were also a postillion, four persons in the carriage, and two servants behind, and the whole of this was drawn by one flea. In his " Histoire Naturelle des Insectes Apteres," Baron Walck- enaer relates the following marvellous instance of industry, patience, and dexterity : " I think it is about fifteen years ago, that the whole population of Paris could see the following wonders exhibited on the Place de la Bourse for sixty centimes. They were the learned fleas. I have seen and examined them with entomological eyes, assisted by a glass. "Thirty fleas went through military exercise, and stood upon their hind legs, armed with pikes, formed of very small splinters of wood. " Two fleas were harnessed to and drew a golden carriage with APTERA. 29 four wheels and a postillion. A third flea was seated on the coach- box, and held a splinter of wood for a whip. Two other fleas drew a cannon on its carriage ; this little trinket was admirably finished, not a screw or a nut was wanting. These and other wonders were performed on polished glass. The flea-horses were fastened by a gold chain attached to the thighs of their hind legs, which I was told was never taken off. They had lived thus for two years and a half, not one having died during the period. To be fed, they were placed on a man's arm, which they sucked. When they were unwilling to draw the cannon or the carriage, the man took a burning coal, and on it being moved about near them, they were at once roused, and re- commenced the performances.'' The learned fleas were the admiration and amazement of Paris, Lyons, and the chief provincial towns of France, in 1825. But how, one will ask, was it possible in a large public room to see this wonderful sight ? And it is necessary that this should be explained. The spectators were seated in front of a curtain, pro- vided with magnifying glasses, through which they looked, as they would at a diorama of landscapes or buildings. But let us return to the natural history of our insect. The female flea lays from eight to twelve eggs, which are of oval shape, smooth, viscous, and white. Contrary to what one might think, a priori, the flea does not fix its eggs to the skin of its victims. She lets them drop on the ground, between the boards of floors, or old furniture, and among dirty linen and rubbish. M. Defrance has remarked that there are always found mixed with the eggs a certain number of grains of a brilliant black colour, which are simply dried blood. This is a provision which the foreseeing mother has prepared at our expense to nourish her young offspring. In four or five days in summer, and in eleven days in winter, one may see coming out of these eggs small, elongated larvae, of cylindrical form, covered with hair, and divided into three parts, the last provided with two small hooks. The head is scaly above, has two small antennae, and is without eyes. These larvae are without limbs, but they can twist about, roll themselves over and over, and even advance pretty fast by raising their heads. Though at first white, they become afterwards of a reddish colour. About a fortnight after they are hatched they cease to eat, and are immovable, as if about to die. They then commence to make a small, whitish, silky cocoon, in which they are transformed into pupae. In another fortnight these pupae become perfect insects. 3O THE INSECT WORLD. A most remarkable trait, and unique among insects, has' been observed in the flea. The mother disgorges into the mouths of the lame the blood with which she is filled. The flea is most abundant in Europe and the North of Africa. Certain circumstances particularly favour its multiplication; being most abundant in dirty houses, in barracks, and in camps; in deserted build- ings, in ruins, and in places frequented by people of uncleanly habits. Other kinds of fleas live on animals, as, for example, the cat flea, the dog flea, and those of the pigeon and poultry. We shall say a few words about a peculiar species which abounds in all the hot parts of America, but principally in the Brazils and the neighbouring countries. This formidable species is the Chigo (Pulex penctrans}. The chigo, called also the tick, is smaller than the common flea. It is flat, brown with a white spot on the back, and is armed with a strong pointed stiff beak, provided with three lancets. It is with this instrument that the female attacks man with the intention of lodging in his skin and bringing forth her young there. The chigo attacks chiefly the feet. It slips in between the flesh and the nails, or gets under the skin of the heel. Notwithstanding the length of the animal's beak, introducing itself beneath the skin does not at first cause any pain ; but after a few days one is made aware of its presence by an itching, which, though at first slight, gradually increases, and ends by becoming unbearable. The chigo, when under the skin, betrays itself by a bump outside. Its body has now become as large as a pea ; in the attacked skin a large brown bag containing matter is formed. In this bag are col- lected the eggs, which issue from an orifice in the posterior extremity, and are not hatched in the wound itself, as was long thought to be the case. The chigoes are an object of terror to the Brazilian negroes. These formidable parasites sometimes attack the whole of the foot, which they devour, and thus bring on mortification ; many negroes losing the bones of some of their toes by the ravages of these dangerous creatures. To guard against their attacks, they wear thick shoes, and examine their feet carefully every day. The plan usually followed in the Brazils to prevent the chigoes from injuring the feet, is to employ children, who, by their sharpness of sight, can easily perceive the red spot on the skin where the chigo has entered. These children are in the habit of extracting the insect from the wound by means of a needle. But this is not without risk ; as, if any portion of the insect remains in the wound, a dangerous APTERA. 3 1 inflammation may ensue. For this reason, operators who are re- nowned for their skill are much sought after, flattered, and rewarded by the poor negroes of the plantations. The Head Louse (Pediculus capitis, Fig. 18) is an insect with a flat body, slightly transparent, and of greyish colour, spotted with black on the spiracles, soft in the middle, and rather hard at the sides. The head, which is oval, is furnished with two thread-like antennae, composed of five joints, which are constantly in motion while the creature is walking ; it is also furnished with two simple, round, black eyes ; and lastly, with a mouth. In the front of the head is a short, conical, fleshy nipple. This nipple contains a sucker, or rostrum, which the animal can put out when it likes, and which, when extended, represents a tubular body, terminating magnified. in six little pointed hooks, bent back, and serving to retain the instrument in the skin. This organ is surmounted by four fine hairs, fixed to one another, and seated in its interior. It is by means of this complicated apparatus that the louse pricks and sucks the skin of the head. The thorax is nearly square, and divided into three parts by deep incisions. The abdomen, strongly lobed at the sides, is composed of eight rings, and is provided with sixteen spiracles. The limbs consist of a trochanter, a thigh, a shank, and a tarsus of a single joint, and are very thick. A strong nail, which folds back on an indented projection, thus forming a pincer, ter- minates the tarsus. It is with this pincer that the louse fastens itself to the hair. Lice are oviparous. Their eggs, which remain sticking to the hair, are long and white, and are commonly called " nits." The young are hatched in the course of five or six days ; and in eighteen days are able to reproduce their kind. Leuwenhoek calculated that in two months two female lice could produce ten thousand ! ^ Other naturalists have asserted that the second generation of a single indi- vidual can amount to two thousand five hundred, and the third, to a hundred and twenty-five thousand ! Happily for the victims of these disgusting parasites, their reproduction is not generally to this pro- digious extent. Many means are employed to kill lice. Lotions of the smaller centaury or of stavesacre, and pomatum mixed with mercurial oint- ment, are very efficacious. But the surest and easiest remedy is to put plenty of oil on the head. The oil kills the lice by obstructing their tracheae, and thus stopping respiration. 32 THE INSECT WORLD. There are other kinds of lice, but we will only mention the louse which infests beggars and people of unclean habits, Pediculus humanus carports, producing the complaint called phthiriasis. In the victims of this disease these parasites increase -with fearful rapidity. This dreadful disorder is often mentioned by the ancients. King Antiochus, the philosopher Pherecydes of Scyros, the contemporary and friend of Thales, the dictator Sylla, Agrippa, and Valerius Maximus, are said to have been attacked by phthiriasis, and even to have died of it Amatus Lusitanus, a Portuguese doctor of the six- teenth century, relates that lice increased so quickly and to such an extent on a rich nobleman attacked with phthiriasis, that the whole duty of two of his servants consisted in carrying away, and throwing into the sea, whole basketfuls of the vermin, which were continually escaping from the person of their noble master. Little is known at the present day of the details of this complaint, though it is observed frequently enough in some parts of the south of Europe, where the dirty and miserable inhabitants are a prey to poverty and uncleanliness two misfortunes which often go together. In Gallicia, in Poland, in the Asturias, and in Spain, we may find many victims of phthiriasis. Lice increase with such rapidity on persons thus attacked, that it is common to attribute their appearance to spontaneous generation alone. But the prodigious rapidity of reproduction in these insects sufficiently explains their increase, especially when it is admitted that it is possible for the female louse to reproduce young without the agency of the male. The Thysanura or " Skip Tail " tribe are small insects, which are better known on account of the beauty of their microscopic body scales than for any interesting habits or instincts. They do not undergo metamorphosis. The Fish Scale or Lepisma saccharina, and the Skip Tail or Podura plitmfaa belong to the Thysanura. 33 II. DIPTERA. ALL suctorial insects which in the perfect state possess only two membranous wings, are called Diptera, from two Greek words Si's, twice, and Trrfpbv, wing. The Diptera were known and scientifically described at a very- early date. They are frequently mentioned by Aristotle in his "History of Animals;" and he applied the term to the same insects as now constitute the order. The absence of the second wings, common to other insects, which are in this case replaced by two appendages, which have received the name of balancers,* because they serve to regulate the action of flight, constitutes the chief characteristic of the Diptera. Let us, however, give a glance at their other organs, which have more or less affinity with those which exist in other classes of insects, pre- serving, nevertheless, their own especial characteristics. The mouth, for instance suited for suction only is in the form of a trunk, and is composed of a sheath, a sucker, and two palpi. The antennae are generally composed of only three joints. The eyes usually two in number are very large, and sometimes take up nearly the whole of the head. They are both simple and compound. The wings are membranous, delicate, and veined ; the limbs long and slight. In giving the history of the principal types of Diptera, we shall explain more fully the formation of these organs. The Diptera, by their rapid flight, enliven both the earth and the air. The different species abound in every climate, and in every situation, some inhabiting woods, plains, fields, or banks of rivers ; others preferring our houses. They like the neighbourhood of vegeta- tion, choosing either the flowers, the leaves, or the stems of the trees of our woods, our gardens, or our plantations. Their food varies * Sometimes called halteres. ED. 34 THE INSECT WORLD. very much; and the formation of the sucker is regulated by it. Some imbibe blood, others live on the secretions of animals. Their chief nourishment, however, consists of the juices of flowers, on whose brilliant corollas the Diptera abound, either plundering from every species indiscriminately, or attaching themselves to some particular kind. They display the most wonderful instinct in their maternal care, and employ the most varied and ingenious precautions to preserve their progeny. The Diptera, besides their variety and the number of their species, are remarkable on account of their profusion. The myriads of flies which rise from our meadows, which fly in crowds around our plants, and around every organised substance from which life has departed, some of which even infest living animals, are Diptera. The profusion with which they are distributed over the face of the globe, causes them to fulfil two important duties in the economy of Nature. On the one hand, they furnish to insectivorous birds an inexhaustible supply of food ; on the other, they contribute to the removal of all decaying animal and vegetable substances, and thus serve to purify the air which we breathe. Their fecundity, the rapidity with which one generation succeeds another, and their great voracity, added to the extraordinary quickness of their reproduction, are such that Linnaeus tells us that three flies, with the generations which spring from them, could eat up a dead horse as quickly as a lion could. These Diptera, which are worthy of so much attention, and deserve so much study with regard to the part they play in the general economy of Nature, are an object of fear and repulsion when one considers their relations to us and other animals. Gnats and mosquitoes suck our blood ; the gad-fly and the species of Asilus attack our cattle. The order Diptera is composed of a great number of families, which are again divided into tribes, each comprising several genera. We shall only notice the more remarkable genera of Diptera. M. Macquart, the learned author off "L'Histoire Naturelle des Dipteres,"* divides this great class of insects into two principal groups. In one of these groups, the antennae are formed of at least six joints, and the palpi of four or five : these are called Nemocera. In the other, the antennae consists only of three joints, and the palpi of one or two : these are the Brachycera. The Nemocera may generally be distinguished from the other Diptera, independently of the difference in the antennae and palpi, by * " Suites k Buffon." 2 vols. 8vo. DIPTERA. 35 the slenderness of the body, the smallness of the head, the shape of the thorax, and the length of the feet and wings. The result of this organisation is a graceful, light, and aerial form NEMOCERA. Abounding everywhere, the Nemocera live, some on the blood of man and animals, some on small insects, and others on the juices of fragrant flowers. From vrina., thread ; K^pas, horn. In all climates, in every latitude, in the fields and woods, even in our dwellings, they may be seen fluttering and plundering. The Nemocera are divided into two families, that of the Culiddtz, of which the gnat (Culex), which has a long, thin trunk, and a sucker provided with six bristles, is a member ; and that of the Tipulida, which have a short thick trunk, and a sucker having two bristles. We will begin our examination with the Gnat ( Culex pipiens\ of Figs. 19 and 20. The Gnat (.Culex pipiens). which Re'aumur, in his "Memoires pour servir a 1'Histoire des Insectes," has given such a curious and complete history. " The gnat is our declared enemy," says Reaumur, in the introduction to his memoir, "and a very troublesome enemy it is. However, it is well to make its acquaintance, for if we pay a little attention we shall be forced to admire it, and even to admire the instrument with which it wounds us. Besides which, throughout the whole course of its life it offers most interesting matter of investigation to those who are curious 36 THE INSECT WORLD. to know the wonders of Nature. During a period in it's life the observer, forgetting that it will at some time annoy him, feels the greatest interest in its life-history." As this is the case, let us explain the history of these insects, which excite so much interest. The illustrious naturalist we have just mentioned will be our guide. The body of the gnat is long and cylindrical. When in a state of repose one of its wings is crossed over the other. They present a charming appearance when seen through a microscope, their nervures, as well as their edges, being completely covered with scales, Fig. 2i. Antenna of Gnat, magnified. Fig. 22. Head of Gnat, magnified. shaped like oblong plates and finely striated longitudinally. These scales are also found on all the segments of the body. The antennae of the gnat, particularly those of the male, have a fine feathery appearance (Fig. 21). Their eyes, covered with network, are so large that they cover nearly the whole of the head. Some have eyes of a brilliant green colour, but looked at in certain lights they appear red. Fig. 22 shows the head of the gnat with its two eyes, its antennae, and trunk. The instrument which the gnat employs for puncturing the skin, and which is called the trunk (Fig. 23), is well worthy of our atten- tion. That which is generally seen is only the case of those instru- ments which are intended to pierce our skin and suck our blood, and in which they are held, as lancets and other instruments are held in a surgeon's case. The case (Fig. 24) is cylindrical, covered with scales, and terminates in a small knob. Split from end to end that DIPTERA. '37 it may open, it contains a perfect bundle of stings. Reaumur tried to observe, by allowing himself to be stung by gnats, what took place during the attack. He forgot, in watching the operations of the insect, the slight pain caused by the wound, soliciting it as a favour, his only regret being not to obtain it when he wished. Reaumur observed that the compound sting, which is about a line in length, enters the skin to the depth of about three-quarters of a line, and that during that time the case bends into a bow, until the two ends meet. He noticed besides, that the trunk-case of certain Figs. 23 and : nkofG Trunk of Gnat, magnified. Figs. 25, 26, 27. Lancets of the Gnat. gnats was even more complicated than that which we have described. But we will not dwell any longer on this point. Let us now try to give an idea of the construction and com- position of this sting, which, after piercing the skin, draws our blood. According to Reaumur, the sting of the gnat is composed of five parts. He acknowledges, however, that it is very difficult to be certain of the exact number of these parts, on account of .the way in which they are united, and of their form. At the present day we know that there are six. Reaumur, as also Leuwenhoek, thought he saw two in the form of a sword blade with three edges. These have the points reversed, and are serrated on the convex side of the bend (Fig. 25). To form an idea of the shape of the other points, the reader should look at Figs. 26 and 27. He will then see that the gnat's sting is a sword in miniature. The prick made by so fine a point as that of the sting of the gnat 38 THE INSECT WORLD. ought not to cause any pain. " The point of the finest needle," says Rdaumur, " compared to the sting of the gnat, is the same as the point of a sword compared to that of the needle." How is it then that so small a wound does not heal at once ? How is it that small bumps arise on the part that is stung ? The fact is, that it is not only a wound, but it has been imbued with an irritating liquid. This liquid may be seen to exude, under different circumstances, from the trunk of the gnat, like a drop of very clear water. Re'aumur sometimes saw this liquid even in the trunk itself. " There is nothing better," he observes, " to prevent the bad effects of gnat bites than at once to dilute the liquid they have left in the wound with water. However small this wound may be, it will not be difficult for water to be introduced. By nibbing, it will be at once enlarged, and there is nothing to do but to wash it. I have sometimes found this remedy answer very well." The gnat is not always in the form of a winged insect, greedy for our blood. There is a period during which they leave us in repose. This is the larva period. It is in water, and in stagnant water in particular, that the larva of the insect which occupies our attention is to be found. It resembles a worm, and may be found in ponds from the month of May until the commencement of winter. If we desire to follow the larva of the gnat from the beginning, we have only to keep a bucket of water in the open air. After a few days this water will be observed to be full of the larvae of the gnat (Fig. 28). They are very small, and come to the surface of the water to breathe ; for which purpose they extend the opening of a pipe, A, which is attached to the last segment of the body, a little above the surface. They are, con- sequently, obliged to hold their heads down. By the side of the breathing-tube is another tube, B, shorter and thicker than the former, nearly per- pendicular to the body, its orifice being the exterior termination of the digestive tube. At the anus it is fringed with long hairs, having the appearance, when in the water, of a funnel. At the end of the same tube, and inside the hair funnel, are four thin, oval, transparent, scaly blades, having the appearance of fins. They are placed in pairs, of which one emanates from the right side, the other from the left. Fig. 28. Larva of the Gnat. DIPTERA. 39 These four blades or fins have the power of separating from each other. Each segment of the abdomen has on both sides a tuft of hair, and the thorax has three. The head is round and flat, and is provided with two simple brown eyes. Round the mouth are several wattles, furnished with hair, of which two of crescent-like form are the most conspicuous. These tufts move with great quickness, causing small currents of liquid to flow into the mouth, by means of which the necessary food, microscopic insects and particles of vege- table and earthy matter, is brought to the larva. They change their skin several times during their continuance in this state. This latter fact has been remarked by Dom Allou, a learned Carthusian, "whose pleasure," says Reaumur, " consisted in admiring the works of the Almighty, when not occupied in singing his praises." We think it will be interesting to repeat the few lines which accom- pany the mention made by Reaumur of this worthy Carthusian. They appear to us to be well worth reading, even at the present day. " If the pious monks who composed so many societies, possessed, like Dom Allou, the love of observing insects, we might hope that the most essential facts in the history of those little creatures would soon be made known to us. What enjoyment more worthy of the calling they have chosen could these pious men pursue than that which would place before their eyes the marvellous creations of an Almighty Power ? Even their leisure would then incline ^them, to adore that Power, and would furnish them the means to make others do so who are occupied by too serious or too frivolous employments." After having changed its skin three times in a fortnight or three weeks, the larva of the gnat throws off its covering for a fourth time, and is no longer in the larva state. It is changed both in shape and condition. Instead of being oblong, its body is shortened, rounded, and bent in such a way that the tail is applied to the under part of the head. This is the case when the animal is in repose ; but it is able to move and swim, and then, by bending its body and! straightening it again, propels itself through the water. In this new condition, that is to say, in the pupa state (Fig. 29), it does not eat. It no longer possesses digestive organs, but it is necessary, even more than before its meta- thena morphosis, that it should breathe atmospheric air. Besides, the organs of respiration are greatly changed. During the time the insect was in the larva state, it was through the long tube fixed to the posterior part that it received or expelled the air ; but in casting 4O THE INSECT WORLD. its skin it loses the tube, two appendages resembling an ass's ears being for the pupa what the tube was for the larva, the opening of these ears being held above the surface of the water. From this pupa the perfect insect will emerge ; it is developed little by little, and the principal members may be distinguished under the transparent membranous skin which envelopes it. When the insect is about to change from the pupa state, it lies on the surface of the water, straightening the hind part of its body, and extending itself on the surface of the water, above which the thorax is raised. Before it has been a moment in this position, its skin splits between the two breathing trumpets, the split increasing very rapidly in length and breadth. " It leaves uncovered," says Reaumur, " a portion of the thorax of the gnat, easily to be recognised by the freshness of its colour, which is green, and different from the skin in which it was before enveloped. " As soon is the split is enlarged and to do so sufficiently is the work of a moment the fore part of the perfect insect is not long in showing itself; and soon afterwards the head appears, rising above the edges of the opening. But this moment, and those which follow, until the gnat has entirely left its covering, are most critical, and when it is exposed to fearful danger. This insect, which lately lived in the water, is suddenly in a position in which it has nothing to fear so much as water. If it were upset on the water, and the water were to touch its thorax or body, it would be fatal. This is the way in which it acts in this critical position As soon' as it has got out its head and thorax, it lifts them as high as it is able above the opening through which they had emerged, and then draws the posterior part of its body through the same opening ; or rather that part pushes itself forward by contracting a little and then lengthening again, the roughness of the covering from which it desires to extricate itself serving as an assistance. " A larger portion of the gnat is thus uncovered, and at the same time the head is advanced farther towards the anterior end of the covering ; but as it advances in this direction, it rises more and more, the anterior and posterior ends of the sheath thus becoming quite empty. The sheath then becomes a sort of boat, into which the water does not enter ; and it would be fatal if it did. The water could not find a passage to the farther end, and the edges of the anterior end could not be submerged until the other was considerably sunk. The gnat itself is the mast of its little boat. Large boats, which pass under bridges, have masts which can be lowered ; as D1PTERA. Fig. 30. Gnats emerging. soon as the boat has passed the bridge the mast is hoisted up by degrees, until it is perpendicular. The gnat rises thus until it 42 THE INSECT WORLD. becomes the mast of its own little boat, and a vertical mast also. It is difficult to imagine how it is able to put itself in such a singular, though for it necessary, position, and also how it can keep it The fore part of the boat is much more loaded than the other, but it is also much broader. Any one who observes how deep the fore part of the boat is, and how near the edges of its sides are to the water, forgets for the time being that the gnat is an insect that he would willingly destroy at other times. One feels uneasy for its fate ; and the more so if the wind happens to rise, particularly if it disturbs the surface of the water. But one sees with pleasure that there is air enough to carry the gnat along quickly ; it is carried from side to side ; it makes different voyages in the bucket in which it is borne. Though it is only a sort of boat or rather mast, because its wings and legs are fixed close to its body, it is perhaps, in proportion to the size of its boat, a larger sail than one would dare to put on a real vessel one cannot help fearing that the little boat will capsize. * * * As soon as the boat is capsized, as soon as the gnat is laid on the surface of the water, there is no chance left for it. I have some- times seen the water covered with gnats which had perished thus as soon as they were born. It is, however, still more extraordinary that the gnat is able to finish its operations. Happily they do not last long ; all dangers may be passed over in a minute. " The gnat, after raising itself perpendicularly, draws its two front legs from the sheath, and brings them forward. It then draws out the two next 'It now no longer tries to maintain its uneasy position, but leans towards the water ; gets near it, and places its feet upon it; the water is sufficiently firm and solid support for them, and is able to bear them, although burdened with the insect's body. As soon as the insect is thus on the water it is in safety ; its wings are unfolded and .dried, which is done sooner than it takes to tell it, at length the gnat is in a position to use them, and it is soon seen to fly away, particularly if one tries to catch it." One more word about the gnat, whose life is full of such interesting details. Fig. 3 i.-Eggs of the Gnat, magnified. The reader will perhaps not feel much pleasure in learning that the fecundity of these insects is extraordinary. Many generations are born in a single year, each generation requiring only three weeks or a month to arrive at a condition to bring forth a new generation. Thus, the number of gnats which comes into existence in the course DIPTERA. 43 of a year is something fearful. Only a few days after the pupae in a bucket are transformed into gnats, eggs which have been left by the females may be observed on the surface of the water in little clusters. Many species of gnats, known as mosquitoes, are to be found in America. All travellers speak of the sufferings endured by a stranger in that country from the bites of these insects. One can only preserve oneself from these cruel enemies during sleep by hanging gauze, called a mosquito curtain, round the bed. Mosquito curtains are not only necessary in America ; during the hot season, in Spain, throughout the whole of Italy, and a part of the south of France, it is necessary to hang these curtains round the bed, if one wishes to obtain any sleep ; it is also a necessary precaution not to have a light in one's bedchamber, as the sight of it at once attracts these dangerous companions, whose buzzing and stinging prevent any possibility of repose during the whole night. Such is our advice to people who travel in the above-mentioned countries. The Tipulidcs have a narrow, elongated abdomen, and long and slight limbs. The head is round, and the eyes, which are compound, are, especially in the males, very large. The wings, which are long and narrow, are sometimes held wide apart, sometimes horizontally, and sometimes bent so as to form, as it were, a roof. The balancers are naked and elongated ; the abdomen long, cylindrical, and often terminating in a club in the male, and in a point in the female. The antennae, which are longer than the head, are generally composed of from fourteen to sixteen joints, and are sometimes in the form of a comb or saw, sometimes furnished with hair, in form of plumes, bunches, or in a whorl. The larvae live on plants, in the fields, in gardens, and sometimes in woods. The perfect insects, at first sight, resemble gnats, but are without a trunk, or rather their trunk is extremely short, terminating in two large lips, and the sucker is composed of two fibres only.* The larger species of Tipulce, which * The genus Cecidomyia, which belongs to this family, presents the most extraordinary instance of agamo-genesis or reproduction without fertilisation by another individual at present known among insects. Until lately it was almost an axiom with naturalists that no insect was capable of reproduction until it had attained its adult or perfect state. Several Continental observers, some of them without any knowledge of the others' discoveries, have found that the larva: of some of the species of this genus reproduce larvce resembling themselves in every respect ; and what is still more strange, these larvae live in a free state within the parent larvas, feeding upon its tissues, and causing its ultimate destruction. A very interesting article on this subject will be found in the Popular Science Review for the 1st April, 1868. The larva of a species (Cecidomyia tritici) frequently causes much injury to the wheat. ED. 44 THE INSECT WORLD. are commonly known as " Daddy Longlegs," c., and in France as " Tailkurs " and " Couturteres," are found in fields at the end of September and commencement of October. "Although they sometimes fly a considerable distance," says Re'aumur, " when the sun is bright and hot, they generally do not go far; often, indeed, only along the ground, or rather the top of the grass. Sometimes they only use their wings to keep them above the level of the herbage, and to take them along. Their legs, particularly the hind ones, are disproportionately large. They are three times the length of the body, and are to these insects what stilts are to the peasants of marshy and inundated countries, enabling them to pass with ease over the higher blades of grass." One of the smaller species has been termed cuHciformis, on account of its resemblance to the gnat. The smaller, are more active than the larger species which we have mentioned. Not only do they fly more rapidly, but there are some kinds which are continually on the wing. In all seasons, even during the winter, at certain hours of the day, clouds of small insects are seen in the air, which are taken for gnats : they are Tipula. Their flight is worthy of attention ; they generally only rise and fall in the same vertical line. All these flies come from larvae, which resemble very elongated worms, having scaly heads, generally furnished with two very small conical antennas, and certain other organs, for the purpose of obtaining food. Their bodies are jointed without limbs, but nevertheless provided with appendages which supply their place. The larvae of the various species are of very different habits. Some are aquatic, as that of Tipula culidformis, a small species which is very numerous in stagnant waters. It is necessary to say a few words about these worm-like larvae, which are extremely common. They are of a brilliant red colour, and inhabit little oblong bent masses of earth, thickly pierced with holes. Each hole allows a worm to extend its head, and the foremost part of its body, out of the cell, which is made of light spongy matters, remains of decayed leaves, &c. These larvae are transformed into v pupae, in the cell in which they have lived, during the larvae state, losing by this metamorphosis the scaly coverings of the head and of all the exterior parts. They pass into the pupa state, and have the thorax provided with dainty plumes, which probably assist in the action of respiration. This pupa is very active and quick in its movements in the water. When the moment comes for its last metamorphosis, it throws off its feathery covering in much the same manner as the gnat. DIPTERA. 45 Fig. 32 represents Tipula oleracea in the different stages of larva, pupa, and perfect insect. Other species of small Tipultz have aquatic larvae very similar to Fig. 32.-- Daddy Longlegs (Tipula oleracea) those which we have described. Re'aumur remarked that each of these worms is lodged in a thick mass, convex at the top, formed of a transparent and adhesive white jelly. The larvae of the larger Tifulcz are not aquatic, but are of different habits, and live under the ground ; all soil which is not frequently turned is suitable to them, but they are to be found especially in low damp meadows. Re'aumur saw large districts of grassy swamps in Poictou, which, in certain years, furnished very little grass for the cattle, on account of the ravages caused by these larvae. They had also much injured the harvest in the same districts during those years. These larvae appear to require no other food than vegetable mould. Their excrements are, .in fact, according to Reaumur, 46 THE INSECT WORLD. nothing else than dried earth, from which the stomach and intestines of the insect have withdrawn all nourishing matter. Old trees have often hollow cavities occasioned by the decay of the trunk. When these cavities are old, their lower parts are full of a sort of mould, which is in fact half-decayed wood. It is there that the Tipulce often lay their eggs. Rdaumur frequently found the larvae in the trunks of elms or willows, and also in the fleshy parts of certain kinds of mushrooms. He carefully observed the habits of one, which lived under the covering of a mushroom, the Oak agaric (Agaricus quercinus). This larva is round, grey, and resembles an earth-worm. It does not walk, but crawls ; and the places where it stops, or which it passes over, are covered with a sort of brilliant slime, like that left by the snail or slug. M. Guerin-Meneville has published some very interesting remarks on the migrations of the larvae of a particular kind of Tipiila, known by the name of Sciara. We will borrow from that entomologist the following curious details, which will initiate us into one of the most wonderful phenomena in the whole history of insects. These small larvae are without feet, hardly five lines in length, and about the third of a line in diameter. They are composed of thirteen seg- ments, and have small black heads. In some years, during the month of July, may be found on the borders of forests in Norway and Hanover, immense trains of these larvae, formed by the union of an innumerable quantity fixed to each other by a sticky substance. These collections of larvae resemble some sort of strange animal of serpent-like form, several feet long, one or two inches in thickness, and formed by the union of an im- mense number, which cling to each other by thousands, and move on together. The whole society advances thus with one accord, leaving a track after it on the ground, as a material indication of its presence. These strange collections of living creatures form societies, some- times only a few yards long ; but at other times it happens that they form bands from ten to twelve yards in length, of the breadth of a hand and the thickness of a thumb. M. Gue'rin-Me'neville observed columns as many as thirty yards in length. These troops advance as slowly as a snail, and in a certain direction. If they encounter an obstacle as a stone, for instance they cross over it, turn round it, or else divide into two sections, which reunite after the obstacle is passed. If a portion of the column be removed so as to divide it into two parts, it is quickly reunited, as the hindmost portion soon joins that which precedes it Lastly, if the posterior part of this DIPTERA. 47 living ribbon be brought into contact with the anterior, a circle is formed, which turns round and round on the same ground for a long time, sometimes even for a whole day, before breaking, and continu- ing to advance. They are never met with in bad weather, but only when the sun is warm. The curious and astonishing phenomenon of an assembly of larvae without feet, advancing with an equal movement resulting from the individual motion of thousands of little worms, was remarked for the first time, in 1603, by Gaspard Schwenefelt. This naturalist says that the inhabitants of Siberia consider this phenomenon as an indi- cation of a bad harvest if they go towards the mountains ; whereas, if they descend towards the plains, it is the sign of a good one. In 1715 Jonas Ramus mentioned the same phenomenon, recalling a superstition attached to it by the peasants of Norway. This writer informs us that the peasants of that country, on meeting one of these moving columns, throw down their belts or waistcoats on the ground before it. If the orme-drag (that is the name given to the moving column) crosses over this obstacle, it is a good sign ; but on the other hand, if the column turns round the obstacle, instead of crossing it, some mischief may be expected. The same animals were observed in 1845 at Birkenmore, near Hefeld, by M. Rande, Royal Inspector of the Forests of Hanover. M. Guerin-Meneville is of opinion that these larvae, which exist in great numbers in certain districts, sometimes devour all the nutri- tive substances contained in the ground. After having done so, they are obliged to come out of it, in order to seek at a distance a place where they will find food, or perhaps only a suitable place to undergo their metamorphosis. It is then that this singular journey commences. As regards the uniting of these myriads of individuals into columns, M. Guerin-Meneville thinks that it can be explained by the necessity these insects feel for mutual protection against the drying effect of the atmosphere when they are forced to leave the ground. United into masses, and moistened by the glutinous matter which connects them, they can leave their former place of abode without danger j if each were by itself, they would soon perish. Here, as in other cases, union is strength ; and the strength of these larvae lies in this protecting moisture. However it may be explained, the migration of these troops of insects are among the most astonish- ing phenomena of Nature. BRACHYCERA. The Brachycera, from fyaxvs, " short ;" and Ktpas, " a horn " 48 THE INSECT WORLD. these Diptera having short antennas are divided into four groups. In this subdivision the sucker is composed of six bristles. Amongst other families it includes that of the 2abanidi&; the insects belonging to which family are of remarkable strength, and possessed of daring and courage in the highest degree. Their wings are provided with powerful mus-cles, their feet are very strong, and their trunk is provided with six flat, sharp lancets. Distributed over the entire world, their instinct is everywhere the same, it is the desire for blood, at least in the females ; for the males are not so war- like, they do no harm, but live on the juices of flowers. They are chiefly found in woods and pastures, and during the hottest part of the day in summer may be seen flying about seeking for their prey. M. de Saint-Fargeau has described the manner in which the males fly. They may be seen flying hither and thither in the glades of woods, remaining for some time suspended in the air, then darting quickly and suddenly away a yard or two, again taking up the same immovable position, and in each of these movements turning the head to the opposite way from that in which they are going. This naturalist is certain that on these occasions they are watching for the females, which they dart upon. When they have succeeded in doing so, they rise so high as to be out of sight. To this group belongs the genus Tabanus. The first species we shall mention, Tabanus autumnalis (Fig. 33), a common species, is eight or nine lines in length, and of blackish colour. The palpi, the face, and the forehead are grey ; the antennae black ; the thorax grey, striped with brown ; the abdomen spotted with yellow; the legs of a yellowish white; and the outer edge of the wings brown. Another species ( Tabanus bovinus) is twelve lines in length, and of a blackish brown. The palpi, the face, and the forehead are yellow ; the antennas black, with a whitish base ; the thorax, covered with yellow hair, is striped with black ; the posterior edge of the segments of the abdomen pale yellow ; the legs yellowish, with the extremities black, and the exterior edge of the wings yellow. This species is frequently met with in woods. A third species, Chrysops cacutiens (Fig. 34), which belongs to the same family, and of which the generic name Chrysops signifies golden-eyed, torments horses and cattle very much by biting them round the eyes. Its thorax is of a yellowish colour, striped or spotted with black ; the abdomen yellow, and the eyes golden. In the next group of the Brachycera the sucker is composed of DIPT ERA. 49 four bristles, and the antennae generally terminate in a point which appears to be rather a development than an appendage. This group includes a number of genera, but the following only Fig. 33- Tabanus autumnalis. Fig. 34. Chrysops csecutiens. possess sufficient interest to claim our attention. From the Tanystoma we select the families of the Asilida, Empidce, and Bombylidtz. As types of the Brachystomcz we select the Leptidcz and Syrphidtz. The chief characteristic of the Asilidce is strength. All their organs combine to produce this quality, which they display only too much, being as formidable to cattle as the Tabani, but even surpassing those insects in natural cruelty. The Asilidce unceasingly attack other insects, and even those of their own kind. Their trunk is strong ; one of the fibres of the sucker is furnished with small points, turned back, which are intended to hold firmly to the body into which it has entered. They carry on their devastations in the glades of woods and on sunny roads. 5O THE INSECT WORLD. We will mention in this group Asilus crabroniformis (Fig. 35), an insect ten to twelve lines long, having a yellow head, black antennae, and thorax of a brownish yellow. The three first segments of the abdomen are black, the second and third having a white spot Fig. 35. Asilus crabroniformis. Fig. 36. Bombylius major. on each side, the remaining segments are yellow. The wings are yellowish, spotted with black on the inner and hind margin. This species is common over the whole of Europe, and lives at the expense of caterpillars and other insects, of which it sucks the blood with the greatest voracity. The Empida live in the same way as the Asilida, but the males are chiefly nourished by the juices of flowers. DIPTERA. 5 1 "They wage war on other insects," says M. Macquart, in his " Histoire Naturelle des Dipteres," " either when flying or running, and they seize their victims with their feet, which are formed in various ways, and well adapted for their purpose, but it is in the air that their hunting, as well as their amours, chiefly take place. They unite together in numerous companies, which during fine summer evenings whirl like gnats about the water's edge. A singular observation, however, that I have made on the Empis, is, that among the thousands of pairs that I have seen resting on hedges and bushes, nearly all the females were occupied in sucking an insect ; some had hold of small Phryganaz* others of Ephemera ,t and the greater part of Tipulce." The Empida have the trunk bent down, and resembling the beak of a bird ; but the Bombylida, on the contrary, have the trunk extended straight in front. The typical genus which has given its name to this latter group is easily to be recognised by the elegance of the fur which covers its body, the slenderness of its feet, and the length ot its wings, which extend horizontally on each side of the body. Much more common in hot climates than in the North, these insects, the larva? of which are not yet known, take flight in the middle of the day, when the sun's rays are hottest They fly very fast, making a dull buzzing sound, and hover over flowers, from which they draw the juices without settling. Fig. 36 represents the Bombyliiis major, which is common enough throughout the whole of Europe. This insect is from four to six lines long, black, with yellow fur ; the feet light yellow ; and the wings have the edges bordered with a sinuous brown band. The genus Anthrax, belonging to this family, has a different form to Bombylius. The body is much less hairy; the trunk is short and concealed in the mouth ; the wings, which are very large, are clothed, at least in the principal genus, in a garb of mourning, sufficiently remarkable, in which the combinations of black and white are admirably diversified. " Here," says M. Macquart, " the line which separates the two colours is straight ; there it represents gradations, in other cases it is deeply sinuous. Sometimes the dark part shows transparent points, or the glassy part dark spots. This sombre garb, added to the velvet black of the body, gives the Anthrax a most elegant appearance ; * The insects produced from the caddis or case-worm. ED. t May-fly family. ED. E 2 52 THE INSECT WORLD. and while resting on the corolla of the honeysuckle and hawthorn to suck the juice, forms a most striking contrast, and sets forth its beauty no less than that of those lovely flowers." Anthrax sinuata is common in Europe. The family of the Syrphida includes three remarkable types, which we cannot pass over in silence. They are Vermileo, Volucella, and Helophilus. Vermileo de Geeri (Fig. 37), which inhabits the central and southern parts of France, is four or five lines in length. Its face is white ; its forehead grey, bordered with black ; the thorax of a yellowish grey, with four brown stripes in the male ; the abdomen light yellow, spotted with black ; and the wings glassy. Fig. 37 .-Ver Fig. 38. A species of Volucella. The larva of the Vermileo has a thin cylindrical body, capable of bending itself in every direction ; a conical head, armed with two horny points ; and the last segment elongated, flat, elevated, and terminated by four hairy tentacles ; 'at the sides of the fifth segment may be observed a little angle, from which projects a horny retractile point. It is of very singular habits. It makes a small tunnel in the sand, having a conical mouth, where it waits, like the spider, im- movable. As soon as an insect falls into the hole, it raises its head, and squeezing its prey in the folds of its body, devours it, and after- wards throws out the skin. It lives in this way for at least three years before attaining the perfect state. The Volucella (Fig. 38) have a strong resemblance to the humble- bee. Certain kinds make use and abuse of this resemblance to introduce themselves fraudulently into its nests, and to deposit their DIPTERA. 53 eggs therein. When these eggs have hatched, the larvae, which have the mouth armed with two mandibles, devour the larvae of their hosts, the bees. This is the return they make for the hospitality they have received ! The Helophili (Fig. 39; deserve to be mentioned here on account of the singular form of many of their larvae. The head is thick, fleshy, and varying a little in form. But the point by which they are easily to be distinguished from most other larvae is, that they have always very long tails, sometimes, Fi s- 39- A species of Heiophiius. indeed, out of proportion to the length of the body. Re'aumur called these larvae " vers a queue de rat;" they. are known in England as rat-tailed maggots, and their Fig. 40. Larvse 01 a Heiophiius habits are aquatic. Having placed some or them in a bason of water, Reaumur saw that they kept in a perpendicular position at the bottom of the bason, and parallel to one another, the extremities 54 THE INSECT WORLD. of their tails being on the surface of the water. He then increased the depth of the water by degrees ; and, as it got deeper, observed that the tail of each worm became longer. These tails, which at first were only two inches long, at last attained to five. It will be remarked that the body of each worm does not exceed five lines in length. The tail is a peculiar organ, by the aid of which the worm breathes, although its body may be covered by water to the depth of several inches. It is composed of two tubes, one of which shuts into the other, like a telescope. Reaumur calls it the breathing tube. It terminates in a little brown knob, in which, according to Reaumur, are two holes for the purpose of receiving the air, and which have five little tufts of hair, which float on the surface of the water. When the time comes for the meta- morphosis of these worms, they come out of the water and bury themselves in the earth ; the skin then hardens and becomes a sort of cocoon. In this cocoon the insect loses the form of a worm, and takes by degrees that of the pupa, which it keeps until circumstances cause it to throw off its last coverings, and to appear in the winged state. What an eventful life ! what a life full of changes and turns of fortune is that of these insects, which pass the first and longest period of their existence under water, another part of their life under the ground, and, finally, after having existed in these two elements, enjoy, high in the air, the pleasures of flight ! The third group of Brachycera is that of the Dichceta; that is, those flies having two-fibred suckers. Among these are classed the (Esfrt, the Conopes, and the flies properly so called. The genus (Estrus, the Gad, Bot-fly, or Breeze, comprises those formidable insects which attack the horse, the sheep, and the ox.* The labours of Rdaumur, in his admirable Memoirs, and those of M. Joly, Professor of Zoology to the Faculte' des Sciences de Toulouse, who published some most valuable researches on this subject, in 1846, will guide us in the following brief explanation. The following is the description given by M. Joly of the Gad-fly (CEstrus equt) represented in Figs. 41, 42, which are taken from a drawing which accompanies that naturalist's Memoirs. The head of this insect is large and obtuse ; the face light yellow, with whitish silky fur ; the eyes blackish ; the antennae ferruginous ; * Mr. Bates, in his interesting "Naturalist on the Amazons," mentions an (Esfrtts as occurring in those regions, which deposits its eggs in the human flesh, the larva causing a swelling which resembles a boil ED. D1PTERA. 57 the thorax grey ; and the abdomen of a reddish yellow, with black spots. The wings are whitish, not diaphanous, with a golden tint, and divided by a winding band of blackish colour. The feet are palish yellow. This species is found in France, in Italy, and also in the East, Fig. 41. Horse-fly, male (CEstrvs (gasterophilus) equf). Fig. 42. Horse-fly, female (CEstrus (gasterophilus) equf). especially in Persia, and rarely in England. During the months of July and August the CEstrus frequents pastures, and deposits its eggs chiefly on the shoulders and knees of horses (PLATE I.). In order to do this, the female suspends herself in the air for some seconds over the place she has chosen, falls upon it, and with her abdomen bent, sticks her eggs to the horse's hairs by means of a glutinous liquid with which they are provided, and which soon dries. This is repeated at very short intervals. It often happens that from four to five hundred eggs are thus deposited upon the same horse. Guided by a marvellous instinct, the female CEstrus generally places her eggs on those parts of the horse's body which can be most easily touched with the tongue, that is, at the inner part of the knees, on the shoulders, and rarely on the outer part of the mane. The eggs of the CEstrus, which are white and of conical form, Fig. 43. Eggs of the Gad-fly (CEstrus (gasterophilus) equf) deposited on the hairs of a horse. adhere to the horse's hair, as shown in Fig. 43. They are furnished with a lid, which at the time of hatching opens, to allow the exit of 58 THE INSECT WORLD. the young larva, which takes place, according to M. Joly, about twenty days after they are deposited. In fact, it is not in the egg state, but really in that of the larva, that the horse, as we shall explain, takes into his stomach these parasitical guests, to which Nature has allotted so singular an abode. When licking itself, the horse carries them into its mouth, and afterwards swallows them with his food, by which means they enter the stomach. It is a remarkable fact that it is sometimes other insects, as the Tabania for instance, that by their repeated stinging cause the horse to lick himself, and thus to receive his most cruel enemy. In the perilous journey they have to Fig. 44. Portion of the stomach of the horse, and larvae of CEstrus (gasterophilus) equi. perform from the skin of the horse to his stomach, many of the larvae of the CEstrus, as may be supposed, are destroyed, ground by the teeth of the animal, or crushed by the alimentary substances. There is hardly one CEstrus in fifty that arrives safely in the stomach of the horse ; and yet if one were to open a horse which had been attacked by the CEstri, the stomach would be nearly always found to have many of the larvse sticking to its inside. Fig. 44, taken from a drawing which accompanies M. Joly's Memoirs, represents the state of a horse's stomach attacked by the Gad-fly larvse. The larvse are of a reddish yellow, and each of their segments is armed at the posterior edge with a double row of triangular spines, DIPT ERA. 59 large and small alternately, yellow at the base, and black at the point, which is always turned backwards. The head is furnished with two hooks, which serve to fasten the larva to the internal coats of the stomach. The spines with which the whole surface of the body is furnished contribute to fix it more perfectly, preventing the creatures, by the manner in which they are placed, from being carried away by the food which has gone through the first process of digestion. It is probable that this larva, so singularly deposited, is nourished by the mucus secreted by the mucous membrane of the stomach, and that it breathes the air which the horse swallows with its food during the process of deglutition. It must be acknowledged, however, that it is in the midst of a gaseous atmosphere which is very unhealthy, for nearly all the gases generated in the stomach of the horse are fatal to man and to the generality of animals, as they consist of nitrogen, carbonic acid, sulphuretted hydrogen, and carburetted hydrogen. To explain how the insect can live under such circum- stances, M. Joly has suggested the following ingenious hypothesis : " When the stomach which the larva inhabits," says this learned naturalist, " contains only oxygen, or air that is nearly pure, the insect opens the two lips of the cavity which contains the spiracles, and breathes at its ease. When the digestion of the alimentary substance generates gas which is unfit for respiration, or when the spiracles run the risk of being obstructed by the solid or liquid substances contained in the stomach, it shuts the lips, and continues to live on the air contained in its numerous tracheae." " Whatever may be the value of this explanation," adds M. Joly, " it is nevertheless very curious to see an insect pass the greater part of its life in an atmosphere which would be instantly fatal to mdst animals, and in an organ where, under the government of life, chemical processes bring about the most wonderful changes of the food into the substance of the animal itself. But how can the insect itself resist the action of these mysterious powers, and remain alone intact in the midst of all these matters which are unceasingly changing and decomposing? This is another question which it is difficult, or rather impossible, to explain in the present state of science ; another enigma which humbles our pride, and of which He who has created both man and the worm alone knows the secret." Arrived at a state of complete development, the larva of the CEstnis imprisoned in the stomach of the horse leaves the membrane to which it has been fixed, then directing the anterior part of its body towards the pyloric opening of the stomach, allows itself to be 60 THE INSECT WORLD. carried away with the excrementitious matter. It traverses, mixed with the excrementary bolus, the whole length of the intestinal canal, leaves it by the anal orifice, and on touching the ground at once seeks a suitable place to go through the last but one of its metamorphoses. The skin then gets thick, hardens, and becomes black. All the organs of the animal are composed of a whitish amorphous pulp, which soon assumes its destined form, and the insect becomes perfect. \ * / 4S- Bot-fly (CEstrus b It then lifts a lid at the anterior part of its cocoon, emerges, dries its wings, and flies off. . The Bot-fly (CEstrus bovis, Fig. 45) has a very hairy body, large head, the face and forehead covered with light yellow hair, the eyes brown, and the antennae black. The thorax is yellow, barred with black ; the abdomen of a greyish white at the base, covered with black hair on the third segment, and the remainder of an orange yellow ; the wings are smoky brown. As soon as the cattle are attacked, they may be seen, their heads and necks extended, their tails trembling, and held in a line with the body, to rush to the nearest river or pond, while such as are not attacked disperse (PLATE II.). It is asserted that the buzzing alone of DIPT ERA. 63 the (Estrus terrifies a bullock to such an extent as to render it un- manageable. As for the insect, it simply obeys its maternal instinct, which commands it to deposit its eggs under the skin of our large ruminants. Let us now explain how the eggs of the- (Estrus, deposited in the skin of the bullock, accommodate themselves to this strange abode. The mother insect makes a certain number of little wounds in the skin of the beast, each of which receives an egg, which the heat of the animal serves to bring forth. It is a natural parallel to the arti- ficial way which the ancient Egyptians invented of hatching the eggs of domestic fowls, and which has been imitated badly enough in our day. Directly the larva of the Bot-fly is out of the egg and lodged be- tween the skin and the flesh of its host, the bullock, it finds itself in a place perfectly suitable to its existence. In this happy condition the larva increases in growth, and eventually becomes a fly in its turn. Those parts of the animal's body in which the larvas are lodged are easily to be recognised, as above each larva may be seen an eleva- tion, a sort of tumour, termed a bot a bump, as Reaumur calls it, comparing it more or less justly to the bump caused on a man's head by a severe blow. Fig. 46, taken from a drawing in Reaumur's Memoirs, represents the bots of which we speak. The country people are well aware of the nature and cause of these bots. They know that each one contains a worm, that this worm comes from a fly, and that later it will be transformed into a fly itself. Each of these bots has in its interior a cavity, occupied by a larva, which, as well as the bot, increases in size as the larva be- comes developed. It is generally on young cows or young bullocks in fact, on cattle of from two to three years of age that these tumours exist, and they are rarely to be seen on old animals. The fly, which by piercing the skin occasions these tumours, always chooses those whose skin offers little resistance. Each tumour is provided with a small opening, by which the larva breathes. In order to examine the interior of the cavity, Reaumur opened some of these tumours, either with a razor or a pair of scissors. He found them in a most disgusting state. The larva is lodged in a regu- lar festering wound, matter occupying the bottom of the cavity, and the head of the worm is continually, or almost continually, plunged in this liquid. " It is most likely very well off there," says Reaumur ; and he adds that this matter appears to be the sole food of the larva. 64 THE INSECT WORLD. " The position of a horned beast," observes the great naturalist, " which has thirty or forty of these bumps on its back, would be a very cruel one, and a terrible state of suffering, if his flesh were con- tinually mangled by thirty or forty large worms. But it is probable they cause no suffering, or at least very little, to the large animal. Fig 46. Bumps produced on Cattle by the larvae of the Bot-fly. Besides," continues Reaumur, " those cattle whose bodies are the most covered with bumps, not only show no signs of pain, but it does not appear that they are prejudicial to them in any way." Reaumur tried to discover how the larva, when arrived at its full growth, succeeds in leaving its abode, as the opening is smaller than its own body. " Nature," says Reaumur, " has taught this worm the surest, the gentlest, and the most simple of methods, the one to which surgeons often have recourse to hold wounds open, or to enlarge them. They DIPTERA. press tents into a wound they wish to enlarge. Two or three days before the worm wishes to come out, it commences to make use of its posterior part as a tent, to increase the size of its exit from its habitation. It thrusts it into the hole and draws it out again many times in the course of two or three days, and the oftener this is re- peated, the longer it is able to retain its posterior end in the opening, as the hole becomes larger. On the day preceding that on which the worm is to come out, the posterior part is to be found almost con- tinually in the hole. At last, it comes out backwards, and falls to the ground, when it gets under a stone, or buries itself in the turf; remaining quiet and preparing for its last transformation. Its skin hardens, the rings disappear, and it becomes black. Thenceforth the insect is detached from the outer skin, which forms a cocoon, or box. At the front and upper part of the cocoon is a triangular piece, which the fly gets rid of when it is in a fit state to come into the open air." Fig. 47, taken from drawings in Reaumur's Memoirs, represents the imago of the (Estrus leaving the cocoon. The reader is, most likely, desirous to know with the aid of what instrument the CEstrus is able to pierce the thick skin of the ox. The female only is pos- sessed of this instrument, which is situated in the posterior ex- tremity of the body. It is of a shiny blackish brown colour, and as it were covered with scales. By pressing the abdo- men of the fly between one's two fingers it is thrust out. Re'aumur observed that it was formed of four tubes, which could be drawn the one into the other, like the tubes of a telescope (Fig. appears to terminate in five small scaly knobs, which are not placed on the same line, but are the ends of five different parts. Three of these knobs are furnished with points, which form an instrument well fitted to operate upon a .hard thick skin. United together, they form a cavity similar to that of an auger, and terminating in the form of a spoon. Fig. 48. Ovipositor of the Bot-fly (CEstrus btrvis). The last of these 66 THE INSECT WORLD. The Gad-fly, or Breeze-fly of the sheep, (Estrus (Cephalemyia ovis), has obtained notoriety on account of its attacking those animals. Even at the sight of this insect the sheep feels the greatest terror. As soon as one of them appears, the flock becomes disturbed, the sheep that is attacked shakes its head when it feels the fly on its nostril, and at the same time strikes the ground violently with its fore-feet ; it then commences to run here and there, holding its nose near the ground, smelling the grass, and looking about anxiously to see if it is still pursued. It is to avoid the attacks of the Cephalemyia that during the Fig. 49. Cephalemyia ovis. hot days of summer sheep lie down with their nostrils buried in dusty ruts, or stand up with their heads lowered between their fore- legs, and their noses nearly in contact with the ground. When these poor beasts are in the open country, they are observed assembled with their nostrils against each other and very near the ground, so that those which occupy the outside are alone exposed (PLATE III.). The Cephalemyia ovis (Fig. 49) has a less hairy head, but larger in proportion to the size of its body than the Gad-fly (Gasterophilus cqut). Its face is reddish; its forehead brown with purple bars; its eyes of a dark and changing green; its antennas black, its thorax sometimes DIPTERA. 69 grey, sometimes brown, 'bristling with small black turbercles ; the ab- domen white, spotted with brown or black ; and the wings hyaline. The Cephalemyia (CEstrus) ovis is to be found in Europe, Arabia, Persia, and in the East Indies. It lays its eggs on the edges of the animal's nostrils, and the larva lives in the frontal and maxillary sinuses. It is a whitish worm, having a black transverse band on each of its segments. Its head is armed with two horny black hooks, parallel, and capable of being moved up and down and laterally. Underneath, each segment of the body has several rows of tubercles of nearly spherical form, surmounted by small bristles having reddish points, and all of them bent backwards. "These points," says M. Joly, " probably serve to facilitate the progress of the animal on the smooth and slippery surfaces of the mucous membranes to which it fixes itself to feed, and perhaps also to increase the secretion of these membranes by the irritation occasioned by the bristles with which they are furnished."* Fixed by means of these hooks to the mucous membrane, which it perforates, the larva nourishes itself with mucus, and lives in this state, according to M. Joly, during nearly a whole year. A,t the end of this time it comes out, following the same course by which it entered, falls to the ground, and burying itself to the depth of a few inches, is transformed into a pupa. The cocoon is of a fine black colour. Thirty or forty days after its burial it emerges in the perfect state, and de- ^ 50 _ Conop& taching the lid at the anterior end of the cocoon by the aid of its head, which has increased considerably in size, takes flight. Notwithstanding the formidable appearance of their trunks, the habits of the perfect Conopes (Fig. 50) are very quiet. In the adult state they are only to be seen on flowers, of which they suck the honeyed juice. But with their larvae the case is otherwise. These latter live as parasites on the humble-bees (Bombt). Latreille saw the Conops rufipes issue in the perfect state from the body of a humble- bee, through the intervals of the segments of the abdomen. * " Recherches sur les CEstrides en general, et particulierement sur les CEstres qui attaquent 1'homme, le cheval, le bceuf, et le mouton." Par N. Joly, Pro- fesseur a la Faculte des Sciences de Toulouse. P. 63. Lyons, 1846. THE INSECT WORLD. The Mutides form that great tribe of Diptera commonly known as flies, and which are distributed in such abundance over the whole world. Faithful companions of plants, the flies follow them to the utmost limits of vegetation. At the same time they are called upon by Nature to hasten the disso- lution of dead bodies. They place their eggs in the car- cases of animals, and the larvae prey upon the corrupt flesh, thus quickly ridding the earth of those fatal causes of infection to its inhabitants. The organs of these insects are also infinitely modified, in order to adapt them to their various functions. M. Macquart divides the Muscides into three sections the Creophili, the Antho- myzides, and the Acalyptera. The Creophili have the strongest organisation ; their movements and their flight are rapid. The greater part feed on the juices of flowers, some on the blood or the humours of animals. Some deposit their eggs on different kinds of insects, others on bodies in a state of decom- position, some again are viviparous. The insects of the genus Echinomyia, for in- stance (Fig. 51), derive their nourishment from flowers. They deposit their eggs on caterpillars, and the young larvae on hatching penetrate their bodies and feed on their viscera. How surprised, sometimes, is the naturalist, who, after carefully preserving a chrysalis, and awaiting day by day the ap- pearance of the beautiful butterfly of which it is the coarse and mysterious envelope, sees a cloud of flies emerge in place of it ! But there is another singular manoeuvre performed by some of the species of the Diptera with which we are at present occupied to Fig. 51. Echinomyia grossa. DIPTERA. 71 prepare an abundant supply of provision for their larvae as soon as they are hatched. The following are the means they employ. It is well known that certain fossorial Hymenoptera carry their prey other insects which they have caught, weevils, flies, &c., and which they intend should serve as food for their own larvae into their subterranean abodes. These Diptera, spying a favourable moment, slip furtively into their retreats, and deposit their eggs on the very food which was intended for others. Their larvae, which are soon hatched, make great havoc among the provisions gathered together in the cave, and cause the legitimate proprietors to die of starvation. " This instinct," says M. Macquart, " is accompanied by the greatest agility, obstinacy, and audacity, which are necessary to carry on this brigandage ; and, on the other hand, the Hymenoptera, seized with fear, or stupefied, offer no resistance to their enemies, and although they carry on a continual war against different insects, and particularly against different Muscides, they never seize those of whom they have so much to complain, and which, nevertheless, have no arms to oppose them with." The Sarcophagtz are a very common family of Diptera, and are chiefly to be found on flowers, from which they steal the juice. The females do not lay eggs, but are viviparous. Reaumur, with his usual care, observed this remarkable instance of viviparism proved in a fly, which seeks those parts of our houses where meat is kept to deposit its larvae. This fly is grey, its legs are black, and its eyes red. When one of them is taken and held between the fingers, there may often be seen a small, oblong, whitish, cylindrical worm come out of the posterior part of the body, and shake itself in order to disengage itself thoroughly. It has no sooner freed itself than the head of another begins to show. Thirty or forty sometimes come out in this manner, and, on pressing the abdomen of the fly slightly, more than eighty of these larvae may sometimes be made to come out in a short space of time. If a piece of meat be put near these worms, they quickly get into it, and eat greedily. They grow rapidly, attaining their full size in a few days, and make a cocoon of their skin, from which in a certain time the imago issues. If the body of one of these ovoviviparous flies (for the eggs hatch within the parent) be opened, a sort of thick ribbon of spiral form is soon seen. This ribbon appears at first sight to be nothing but an assemblage of worms, placed alongside of and parallel to one another; Each worm has a thin white membranous envelope, similar to 72 THE INSECT WORLD. those light spiders' webs which float about in autumn, which the French callyf/r de la merge, and we denominate gossamer. The fecundity of this fly is very great, for, in the length of a quarter of an inch, the envelope in which these small worms are enclosed contains 2,000 of them. Therefore this ribbon, being two inches and a half long, contains about 20,000 worms. The members of the genus Stomoxys, though nearly related to the house-fly, differ from it very much in habits. They live on the blood of animals. The Stomoxys calcitrant is very common in these climates. Its palpi are tawny yellow, antennae black, thorax striped with black, abdomen spotted with brown, and its trunk hard, thin, and long. It deposits its eggs on the carcases of large animals. The Golden Fly, Lucilia Casar, lays its eggs on cut-up meat, or Fig. 52. Lucilia hominivorax. on dead animals. It is only three or four lines in length, of a golden green, with the palpi ferruginous, antennae brown, and feet black. A species of this genus, the Lucilia hominivorax, has lately ob- tained a melancholy notoriety. We are indebted to M. Charles Coquerel, surgeon in the French Imperial navy, for the most exact information concerning this dangerous Dipteron, and the revelation of the dangers to which man is liable in certain parts of the globe. But let us first describe the insect, which is very pretty and of brilliant colours. Fig. 52, taken from M. Charles Coquerel's Memoir, represents the larva and the perfect insect, as well as the horny mandibles with which the larva is provided. It is rather more than the third of an inch in length, the head is large, downy, and of a golden yellow. DIPTERA. 73 The thorax is dark blue and very brilliant, with reflections of purple, as is also the abdomen. The wings are transparent, and have rather the appearance of being smoked ; their margins, as well as the feet, are black. This beautiful insect is an assassin. M. Coquerel has informed us that it sometimes occasions the death of those wretched convicts whom human justice has transported to the distant penitentiary of Cayenne. When one of these degraded beings, who live in a state of sordid filth, goes to sleep, a prey to intoxication, it happens sometimes that this fly gets into his mouth and nostrils ; it lays its eggs there, and when they are changed into larvae, the death of the victim generally follows.* These larvae are of an opaque white colour, a little over half an inch in length, and have eleven segments. They are lodged in the interior of the nasal orifices and the frontal sinuses, and their mouths are armed with two very sharp horny mandibles. They have been known to reach the ball of the eye, and to gangrene the eyelids. They enter the mouth, corrode and devour the gums and the entrance of the throat, so as to transform those parts into a mass of putrid flesh, a heap of corruption. Let us turn away from this horrible description, and observe that this hominivorous fly is not, properly speaking, a parasite of man, as it only attacks him accidentally, as it would attack any animal that was in a daily state of uncleanliness. In many works on medicine may be found mentioned a circum- stance which occurred twenty years ago, at the surgery of M. J. Cloquet. The story is perhaps not very agreeable, but is so inte- resting as regards the subject with which we are occupied, that we think it ought to be repeated here. One day a poor wretch, half dead, was brought to the Hotel-Dieu. He was a beggar, who, having some tainted meat in his wallet, had gone to sleep in the sun under a tree. He must have slept long, as the flies had time enough to deposit their eggs on the tainted meat, and the larvae time enough to be hatched, and to devour the beggar's meat. It seems that the larvae enjoyed the repast, for they passed from the dead meat to the living flesh, and after devouring the meat they commenced to eat the * " The majority of convicts attacked by the Lucllia hominivorax," says M. F. Bouyer, captain of the frigate, in " Un Voyage a la Guyane Fran9aise," "have succumbed, despite the assistance of science. Cures have been the exception : in a dozen cases three or four are reported." Tour du Monde, 1866, ler Semestre, p. 318. 74 THE INSECT WORLD. owner. Awoke by the pain, the beggar was taken to the H6tel- Dieu, where he expired. Who would suppose that one of the causes which render the centre of Africa difficult to be explored is a fly not larger than the house-fly? The Tsetse fly (Fig. 53) is of brown colour, with a few transverse yellow stripes across the abdomen, and with wings longer than its body. It is not dangerous to man, to any wild animals, or to the pig, the mule, the ass, or the goat. But it stings mortally the Fig. 53. The Tsetse Fly (Glossi. orsitans). ox ; the horse, the sheep, and the dog, and renders the countries of Central Africa uninhabitable for those valuable animals. It seems to possess very sharp sight. " It darts from the top of a bush as quick as an arrow on the object it wishes to attack," writes a tra- veller, M. de Castelnau. Mr. Chapman, one of the travellers who have advanced the farthest into the middle of Southern Africa, relates that he covered his body with the greatest care to avoid the bites of this nimble enemy ; but if a thorn happened to make a nearly imperceptible hole in his clothing, he often saw the Tsetse, who appeared to know that it could not penetrate the cloth, dart forward and bite him on DIPTERA. 75 the uncovered part. The sucker of blood secretes in a gland placed at the base of his trunk so subtle a poison, that three or four flies are sufficient to kill an ox. The Glossina morsitans abounds on the banks of the African river, the Zambesi, frequenting the bushes and reeds that border it. It likes, indeed, all aquatic situations. The African cattle recognise at great distances the buzzing of this sanguinary enemy, and this fatal sound causes them to feel the greatest fear. Livingstone, the celebrated traveller, in crossing those regions of Africa that are watered by the Zambesi, lost forty-three magnificent oxen by the bites of the Tsetse fly, notwithstanding that they were carefully watched, and had been very little bitten. " A most remarkable feature in the bite of the Tsetse is its perfect harmlessness in man and wild animals, and even calves so long as they continue to suck the cows. We never experienced the slightest injury from them ourselves personally, although we lived two months in their habitat, which was in this case as sharply denned as in many others, for the south bank of the Chobe was infested by them, and the northern bank, where our cattle were placed, only fifty yards distant, contained not a single specimen. This was the more remarkable, as we often saw natives carrying over raw meat to the opposite bank with many Tsetses settled on it. "The poison does not seem to be injected by a sting, or by ova placed beneath the skin, for, when one is allowed to feed freely on the hand, it is seen to insert the middle prong of three portions, into which the proboscis divides, somewhat deeply, into the true skin. It then draws it out a little way, and it assumes a crimson colour, as the mandibles come into brisk operation. The previously- shrunken belly swells out, and, if left undisturbed, the fly quietly departs when it is full. A slight itching irritation follows, but not more than in the bite of the mosquito. In the ox this same bite produces no more immediate effects than in man. It does not startle him, as the gad-fly does ; but a few days afterwards the following symptoms supervene : the eyes and. nose begin to run, the coat stares as if the animal were cold, a swelling appears under the jaw, and sometimes on the navel ; and, though the animal continues to graze, emaciation commences, accompanied with a peculiar flaccidity of the muscles, and this proceeds unchecked until, perhaps months afterwards, purging comes on, and the animal, no longer able to graze, perishes in the state of extreme exhaustion. Those which are in good condition often perish, soon after the bite is inflicted, with staggering and blindness, as if the brain were 76 THE INSECT WORLD. affected by it. Sudden changes ot temperature produced by falls of rain seem to hasten the progress of the complaint ; but in general the emaciation goes on uninterruptedly for months, and, do what we will, the poor animals perish miserably. " When opened, the cellular tissue on the surface of the body beneath the skin is seen to be injected with air, as if a quantity of soap bubbles were scattered over it, or a dishonest awkward butcher had been trying to make it look fat. The fat is of a greenish-yellow colour, and of an oily consistence. All the muscles are flabby, and the heart often so soft that the fingers may be made to meet through it. The lungs and liver partake of the disease. The stomach and bowels are pale and empty, and the gall-bladder is distended with bile. These symptoms seem to indicate, what is probably the case, a poison in the blood ; the germ of which enters when the proboscis is inserted to draw blood. The poison-germ contained in a bulb at the root of the proboscis, seems capable, although very minute in quantity, of reproducing itself. The blood after death by Tsetse is very small in quantity, and scarcely stains the hands in dissection. . . . "The mule, ass, and goat enjoy the same immunity from the Tsetse as man and game. Many large tribes on the Zambesi can keep no domestic animals except the goat, in consequence of the scourge existing in their country. Our children were frequently bitten, yet suffered no harm ; and we saw around us numbers of zebras, buffaloes, pigs, pallahs and other antelopes, feeding quietly in the very habitat of the Tsetse, yet as undisturbed by its bite as oxen are when they first receive the fatal poison. There is not so much difference in the natures of the horse and zebra, the buffalo and ox, the sheep and the antelope, as to afford any satisfactory explanation of the phenomenon. Is a man not as much a domestic animal as a dog ? " The curious feature in the case, that dogs perish though fed on milk, whereas the calves escape so long as they continue sucking, made us imagine that the mischief might be produced by some plant in the locality, and not by Tsetse ; but Major Vardon, of the Madras army, settled that point by riding a horse up to a small hill infested by the insect, without allowing him time to graze, and though he only remained long enough to take a view of the country and catch some specimens of Tsetse on the animal, in ten days afterwards the horse was dead."* * " Missionary Travels and Researches in South Africa," by David Livingstone, LL.D., D.C.L. P. 8l, efsey. London, John Murray, 1857. (The extract in the DIPTERA. 77 The inhabitants of the Zambesi can, therefore, have no domestic animal but the goat. When herds of cattle driven by travellers or dealers are obliged to cross these regions, they only move them during the bright nights of the cool season, and are careful to smear them with dung mixed with milk ; the Tsetse fly having an intense antipathy to the dung of animals, besides being in this season rendered dormant by the lowness of the temperature. It is only by such precautions that they are able to get through this dangerous stage of their journey. The large blue Meat-fly, the familiar representative of the genus Calliphora, is known to all by its brilliant blue and white reflecting abdomen. This fly, which is common everywhere, is the Calli- phora vomitoria on which Reaumur has made many beautiful observations, which we will make known to our readers. If we shut up a blue meat-fly in a glass vase, as Reaumur did, and place near the insect day eggs thereon one after the other, in irregular heaps, of various sizes. The whole of these heaps consist of about two hundred eggs, which are of an iridescent white colour, and four or five times as long as they are broad. In less than twenty-four hours after the egg is laid the larvae is hatched. It is no sooner born than it thinks of feeding, and buries itself in the meat with the aid of the hooks and lancets with which it is provided. These worms do not appear to discharge any solid excrement, but they produce a sticky liquid, which keeps the meat in a moist state and hastens its putrefaction. The larvae eat voraciously and continually ; so much so, that in four or five days they arrive at their full growth. They then take no more nourishment until they are transformed into flies. They are now about to assume the pupa state. In this condition it is no longer necessary for them to remain on the tainted meat, .which has been alike their cradle and their larder, and where until now they were so well off. They therefore leave it and seek a retreat under ground. The larva then assumes a globular form and reddish colour, loses original of this work is from a French translation : "Explorations dans 1'Interieur de 1'Afrique australe, et voyages a travers le continent Sainte-Paul de Loanda a 1' Embouchure du Zambeze, de 1840 a 1846, traduit de 1'Anglais." Pages 93 95.' 8vo. Paris, 1859. -ED. ct a piece of fresh meat, before half a Fig. 54 ._Eggs of the Meat-fly, is passed, the fly will have deposited its (.Catup/wra vomitoria). 78 THE INSECT WORLD. all motion, and cannot any longer either lengthen or shorten, or dilate or contract itself. Life seems to have left it. " It would be considered a miracle," says Reaumur, "if we were told there was any kind of quadruped of the size of a bear, or of an ox, which at a certain time of the year, the beginning of winter for instance, dis- engages itself completely from its skin, of which it makes a box of an oval form ; that it shuts itself up in this box ; that it knows how to close it in every part, and besides that it knows how to strengthen it in such a manner as to preserve itself from the effects of the air and the attacks of other animals. This prodigy is presented to us, on a small scale, in the metamorphosis of our larva. It casts its skin to make itself a strong and well-closed dwelling." If one opens these cocoons only twenty-four hours after the metamorphoses of the worms, no vestige of those parts appertaining to a pupa is to be found. But four or five days afterwards, the cocoon is occupied by a white pupa, provided with all the parts of a fly. The legs and wings, although enclosed in sheaths, are very distinct ; these sheaths being so thin that they do not conceal them. The trunk of the fly rests on the thorax ; one can discern its lips, and the case which encloses the lancet. The head is large and well formed, its large, compound eyes being very distinct. The wings appear still unformed, because they are folded, and, as it were, packed up. It is a fly, but an immovable and inanimate fly ; it is like a mummy enveloped in its cloths. Nevertheless, it is intended this mummy should awake, and when the time comes it will be strong and vigorous. Indeed, it has need of strength and vigour to accomplish the important work of its life. Although its coverings are thin, it is a considerable work for the insect to emerge, for each of its exterior parts is enclosed in them as in a case, much the same as a glove fits tightly to all the fingers of the hand. But that for which the most strength is necessary is the operation of forming the opening of the cocoon, in which as a mummy it is so tightly enclosed. The fly always comes out at the same end of the cocoon, that is, at the end where its head is placed, and also where the head of the larva previously was. This end is composed of two parts of two half cups placed one against the other. These can be detached from each other and from the rest of the cocoon. It is sufficient for the fly that one can be detached, and in order to effect this, it employs a most astonishing means. It expands and contracts its head alternately, as if by dilatation ; and thus pushes the two half cups away from the end of the cocoon. This is not long able to resist the DIPTERA. 79 battering of the fly's head, and the insect at length comes out triumphant. This fly, which should be blue, is then grey ; it, how- ever, comes quickly to perfection, at the end of three hours attaining its ultimate colour ; and in a very short space of time every part of the animal becomes of that firmness and consistency which characterises them. At the same time, the wings, which at the moment it came into the world were only stumps, extend and unfold themselves by degrees. The meat-fly is represented below (Fig. 55). One of the features in the formation of this fly which most attracted the attention of Reau- mur, and which is likely to excite the curiosity of all those who take an interest in insects, is the composition of its trunk. We will, therefore, with that illus- trious observer, take a glimpse at the remarkable and compli- cated apparatus by the aid of which the fly can suck up liquids, and can even taste solid and Crystalline Substances, SUCh Blue-bottle fly (Callipforl \,omitona\ magnified. as sugar. It is no difficult matter to make a fly show its trunk extended to its full extent. One has only to press between the finger and thumb either the two sides of the upper and under part of the thorax. It is thus forced at once to put out its tongue. The trunk appears to be composed of two parts joined together, and forming a more or less obtuse angle (Fig. 56). The first portion Fig 56. Trunk of the Meat-fly. Fig 37. Conical part of the trunk. of the trunk, that which joins the head, is perfectly membranous and in the form of a funnel. We will call it the conical part, and show it separately (Fig. 57). The second portion terminates in a thick mass, in part cartilaginous or scaly, and of a shiny brown colour. Above 8O THE INSECT WORLD. the conical portion are two oblong antennae, without joints, of chestnut colour, and 'furnished with hairs. On ceasing to press the thorax, the membranous conical portion may be seen to draw itself back within its sheath (Fig. 58). The second portion is at the same time drawn into the cavity, but it raises itself by forming a more and more acute angle, so that when it reaches the opening of the cell it is parallel with, and its length is equal to that of the cell, which is quite large enough to receive it. The base lengthens and flattens a little, and conceals the trunk. Let us cause the trunk to extend itself a second time, in order to observe its tip minutely. Here the opening is placed, which may be looked upon as the mouth of the insect, and is provided with two large thick lips (Fig. 59). These lips form a disc, perpendicular to Retractile proboscis of Blue-bottle fly. Extremity on the'proboscis of a fly. the axis of the trunk ; the disc is oval, and is divided into two equal and similar parts by a slit. The lips have each a considerable num- ber of parallel channels situated perpendicularly to the slit. These channels are formed by a succession of vessels placed near each other. On pressing the trunk we see that these vessels are dis- tended by a liquid. Reaumur, from whom we borrow these details, discovered a few of the uses to which this trunk is applied. He covered the interior of a transparent glass vase with a light coat of thick syrup. He then put in some flies, when it was easy to see some of them proceed to fix themselves to the sides of the vase, and regale themselves on the sugary liquid, of which they are very fond. He observed them carefully, and in his admirable work he recom- mends those who are curious to try the experiment, with which, like himself, they will certainly be satisfied. While the body of the trunk is stationary its end is much agitated. It may be seen to move in different ways, and with an astonishing quickness ; the lips acting in a hundred different ways, and always with great rapidity. The small diameter of the disc DIPT ERA. 8 1 which they form lengthens and shortens alternately ; the angle formed by the two lips varies every instant ; they become succes- sively flat and convex, either entirely or partly. All these move- ments, Reaumur remarks, give a high idea of the organisation of the part which performs them. The object of all these movements is to draw the syrup into the interior of the trunk. If we observe the lips (Fig. 60) attentively, it will easily be seen that they touch each other about the centre of the disc, and leave two openings, one in front, the other at the back. The one in front is, one may say, the mouth of the fly, as it is to this opening that the liquid is brought, which is intended to be and is soon introduced into the trunk. Without occupying ourselves for the present with the channel through which pjg. 60. it rises, we may first ask, whatever that channel may be. L jv s { '? e JP"*" ... J ...... ... J ' boscis of a fly. what is the power that lorces the liquid into it ? It is nearly certain that suction is the principal cause of the liquid flowing up the trunk. It would thus be a sort of pump, into which the liquid is forced by the pressure of the external air. The fly exhausts the air from the tube of its trunk, and the drop of liquid which is at the opening penetrates and goes up this channel through the influence of the atmospheric pressure. To this physical pheno- menon must be added the numerous and multiplied movements which take place in the trunk, and which are intended to cause sufficient pressure to drive the liquor which is introduced into the channel upwards. Reaumur wished to know how it was that very thick syrups, and even solid sugar, can be sucked up by the soft trunk of the fly. What he saw is wonderful. If a fly meets with too thick a syrup, it can render it sufficiently liquid ; if the sugar is too hard, it can dis- solve small portions of it. In fact, there exists in its body a supply of liquid, of which it discharges a drop from the end of its trunk at will, and lets this fall on the sugar which it wishes to dissolve, or on the syrup it wishes to dilute. A fly, when held between the fingers, often shows at the end of its trunk a drop, very fluid and trans- parent, of this liquid. " The water poured on the syrup," says Re'aumur, "would not always insinuate itself sufficiently quick into every part of it ; the movement of the fly's lips hastens the operation ; the lips turn over, work, and knead it, so that the water can quickly penetrate it, in the same way as one handles and kneads with one's hands a hard paste which it is wished to soften, by causing the water by which it is covered to mix with it. This, again, is the same G 82 THE INSECT WORLD. means the fly employs with sugar. When the trunk is forced to act upon a grain of irregular and rugged form, on which it cannot easily fasten, its end distorts itself to seize and hold it. It is sometimes very amusing to see how the fly turns over the grain of sugar in different ways ; it appears to play with it as a monkey would with an apple. It is, however, only that it may hold it well in order to moisten it more successfully, and afterwards to pump up the water which has partly dissolved it." Re'aumur often observed a drop of water at the end of the trunks of flies which were perfectly surfeited with food. This drop ascended the trunk, then re-descended to the end, and this many times in suc- cession. It appeared to him that it was necessary for these insects, as for many quadrupeds, to chew the cud, as it were ; that, in order the better to digest the liquid they had passed into their stomachs, they were obliged to bring it back into the trunk that it might return again better prepared. In order to assure himself directly of the reality of his supposition, Reaumur tested the water which a fly, that he says " had got drunk on sugar," had brought back to the end of its trunk ; he found this to be sugar and water. Also, having given a fly currant-jelly, he observed, after it had sufficiently gorged itself, several drops of red liquid in its trunk, and having tasted it, found it had the flavour which, from its appearance, he guessed it would have. The illustrious observer, who had already made all these dis- coveries on the formation and functions of the trunks of insects, often reflected on the fact that the liquors of which flies are most fond are enclosed under the skin of certain fruits, such as pears, plums, grapes, &c., or even under the skin of some animals of which they suck the blood. In order that the trunk of a fly may act under such circum- stances, it is necessary for it to pierce and open the skin. If this is the case, flies ought to be possessed of a lancet. He looked a long time for this lancet, and at last found it. It is situated on the upper side of the part of the trunk which is terminated by the lips ; it is placed in a fleshy groove, and is enclosed in a case. It has a very line point, and is of light colour (Fig. 61). The point is situated in the opening which is to be seen between the lips of the trunk, at its anterior end, through which liquids may pass. That is the only opening of the lips ; and the sucker which takes up the liquid is the same part which we just now called the case of the lancet. Reaumur is so interesting an author that it is difficult to cease quoting him ; but we must continue our review of the principal kinds of Diptera. DIPTERA. 83 The genus Miisca (fly), in which Linnaeus comprised the immense series of Diptera, with the exception of the Tipnlidce, the Tabanidce, the Asilidce, the Bombylida, and the Empidce, is now reduced to the House Fly and a few resembling it. The habits of these trouble- some companions are in conformity with the two great principles of animal life, that is, eating and propagating their species. Flies feed principally on fluids which exude from the bodies of animals ; that is, sweat, saliva, and other secretions. They also seek vegetable juices ; and they may be seen in our houses to feed eagerly on fruits and sweet substances. The common flies deposit their eggs on vegetables, and particu- larly on fungi in a state of decomposition, on dung-heaps, cow dung, &c. They are essentially parasites, settling on both man and beast, to suck up the fluid substances which are diffused over the surface of their bodies. In our dwellings they eat anything that will serve to Fig. 61. Lancet of the Meat Fly. Fig. 62. -House Fly (Muscn. domestica). nourish them. Generation succeeds generation with the greatest rapidity. The House Fly (Musca domestica, Fig. 62) is about three lines in length, ash coloured, with the face black, the sides of the head yellow, and the forehead yellow with black stripes ; the thorax is marked with black lines; the abdomen is pale underneath, and a transparent yellow at the sides, in the males, and is speckled with black. The feet are black ; the wings transparent, and yellowish at the base. This species is extremely plentiful throughout the whole of Europe. Every one knows how annoying it is towards the end of the summer, and especially so in the South of France during the hot season. The Ox Fly (MusctL bovina), a near relation of the house fly, is also very common. It settles on the nostrils, the eyes, and the wounds of animals. The Executioner Fly (Musca carnifex), which is not rare in France, also attacks oxen. It is of a dark metallic green colour G 2 8 4 THE INSECT WORLD. with a slight ash-coloured down. Its forehead is silvery at the front and sides ; the abdomen is edged with black ; the wings hyaline, and yellow at the base. Section of the Anthomyides. The section of Anthomyides com- prises insects which appear to be Creophili whose organisation has become weakened by almost insensible degrees. Their colours vary very much black, grey, and iron-colour are everlastingly shaded and blended together. To that may be added reflections which are above the ground colour, and which change the hues of the little animal according to the incidence of the rays of light. The Antho- myides resemble the genus Musca very closely in their habits as well as in their organisation. In this group of Diptera we will first say a few words about the Anthomia. These flies are to be found in most gardens, and on all flowers, particularly on the heads of Com- positae and Umbelliferas. They often unite in numerous bands in the air, and indulge in the joyous dances to which love invites them. The females deposit their eggs in the ground, and their larvae are there quickly developed. The latter suspend themselves to certain bodies, the same as some lepidopterous chry- salides, in order to transform themselves into pupse. The Anthomyta pluvialis (Fig. 63) is from two to four lines in length, and of a whitish ash-colour. Its wings are hyaline, the thorax has five black spots, and the abdomen three rows of similar spots. We will stop a moment with the Pego- myia, which are very interesting in the larva Fig. 6 3 . Amhomyia pluvialis. state, and which excited the interest and sagacity of Reaumur. The cradle of these Diptera is the interior of leaves. They work as the miners of the vegetable world, in the parenchyma or cellular tissue of the leaf, between the two epidermal membranes. The henbane, the sorrel, and the thistle, especially nourish them. If one holds a leaf in which one of these miners has established itself against the light, one sees the workman boring the vegetable membrane. Its head is armed with a hook, formed of two horny pieces, and leaf. The with this hook it digs into the parenchyma of the leaf. effect of DIPTERA. this digging is visible, as those places become by degrees transparent. Each blow detaches a small portion of the substance of the leaf. It is thus that these miners hollow out galleries for themselves, in which they find shelter, food, and security. Some are changed into pupae in the gallery which they have hollowed out, others go out of the leaves when they are near their final transformation. Section of Acalyptera. The Acalyptera, which are the last of the great tribe of Muscidcz, comprehend the greater number of these insects. Their constitution appears to be peculiar and slow. They live principally in the thickest part of woods, on grasses, and aquatic plants. Fearing the lustre and warmth of the sun, they never draw the nectar from flowers. Their flight is feeble, and they never indulge in those joyous ethereal dances which we have men- tioned when speaking of the preceding groups. Their life is generally melan- choly, obscure, and hidden. Some of them seek decomposed animal and vegetable substances, others living vegetables. We shall only be able in this im- mense group of Musridce to mention a few types which are interesting from various reasons, such as the Helomyzce, the Scatophagce, the Ortalides, the Dad, and the Thyreophorce. The Helomyzce (Fig. 64) live in the woods. Their larvae are deve- loped in the interior of fungi. Reau- mur studied the larvae of the Truffle Helomyza. The head of this fly is ferruginous, its thorax is of a brownish grey, its shoulders of a brownish yel- low, its wings brownish, the abdomen yellow and brown, and the feet red. The larvae of these insects commit depredations for which gourmands will never forgive them, destroying, as they do, their truffles. When one presses between one's fingers a truffle that is in a too advanced state, one feels certain soft parts, which yield under pressure. On Fig. 64. A species of Helomys 6 THE INSECT WORLu. opening the truffle, the lame of the insect of which we are speaking will be found inside. These larvae are white and very transparent. Their mouth is armed with two black hooks, by means of which they dig into the truffle in the same way as other larvae dig into meat. The excretions of these little parasites cause the truffle to become decomposed and rotten. In a few days the larvae become full-grown. They then leave their abode and go into the ground, there to change into pupae. The Ortalidcp. form a tribe which is remarkable for the upright carriage of the wings, which are generally speckled, by the vibratory movement of these organs, and especially for the cradle chosen by them for their progeny in fruits and grains. Nature seems to have assigned to each species its own particular vegetable. We will only mention here the Cherry-tree Orta/is, whose larva lives on the pulp of that fruit. This fly is about a line and a half long. It is of rather a metallic black colour, its head light yellow, the edges of its eyes white, and the tarsi red. The wings have four broad black stripes. The Olive Dacus (Dacus olea, Fig. 65) is a little fly, about half the size of the house fly, of ashy grey colour on the back, its head orange-yellow, its eyes green, and its forehead yellow, marked with two large black spots. The thorax is adorned with four lightish yellow spots, and its hind part, as well as its __! , X/^^^P\^V antennas and wings, are of the 1 j / t* \ ^ same colour. The wings are transparent, reflecting green, Fig. 6s.-Dacus oiex. gold, pink, and blue, according as the rays of light fall upon them, and are remarkable for having a small black spot at their ex- tremity. The abdomen is of a fawn colour or orange-yellow, spotted with black on each side. This fly performs sudden and jerking movements ; it keeps its wings extended, and rather jumps than flies. It is a destructive insect, a perfect scourge, which causes every two or three years a loss of five or six millions of francs to French agriculture. M. Gue'rin-Me'neville has made some valuable observations on the Olive Dacus, and at the request of the Imperial Society of Agriculture of Paris, has indicated the way to preserve the olive from D1PTERA. these ruinous larvae, which generally destroy two crops out of three. We will borrow the following details from this learned entomologist : Fig. 66. ttacked by Dacus oleae. " At the time when the olives are formed the Dacus proceeds to place an egg under the skin of each of the fruits. By means of a little horny instrument, with which the female is provided, and which 88 THE INSECT WORLD. contains a small lancet, she pierces the skin of the olive ; she moves her wings and lays her egg. She afterwards cleans and rests herself, by passing her feet over her head, wings, and other parts of her body. She then flies away, and seeks another olive, to deposit in it another egg ; she repeats this operation until she has placed on as many olives the three or four hundred eggs which she bears." Fig. 66, taken from the Memoir published by M. Guerin- Meneville, in the "Revue Nouvelle" of the isth July, 1847, shows the Dacus laying its eggs on the olive, and the larvae that are already hatched in another of the same fruit. The larvse which succeed these eggs (Fig. 67) are whitish, soft, and without limbs. They pass fifteen or sixteen days in boring a gallery in the pulp of the olive, at Fig. 67. Fig. 68. Larvae of Dacus oleae (magnified and natural size). Gallery formed by larva of Dacus olese. first vertically, until they reach the stone, then on one side, and along the side of the stone. When they have reached the term of their development, they approach the surface, enlarging the first channel and leaving between it and the exterior air only a thin pellicle, in the middle of which may be perceived the first small opening by which the mother had introduced her egg in the com- mencement. Fig. 68, copied from a drawing in the Memoirs of M. Gue'rin- Me'neville, shows the gallery bored round the olive by the larva of the Dacus. The larva thus prepares an easy issue for the perfect insect Its skin then contracts, its body diminishes in length, and is transformed into an oval cocoon, which soon gets brown, and is the chrysalis of the insect. At the side of the head it shows a curved line, a thin suture which marks a sort of cap or door, which, at the time of its hatching, the insect will be easily able to force open with its head. The fly is hatched twelve days after its metamorphosis DIPTERA. 89 from the larva to the pupa. It has thus taken the Dacus twenty-seven to twenty-eight days to arrive at this state, from the time the egg was laid ; besides which, this species, in the warm climates of Provence and Italy, can reproduce itself several times from the beginning of July, the period at which the first flies begin to lay, till the end of autumn. In order to save a considerable portion of the olive crop of these countries, M. Guerin-Meneville has advised hastening the harvest sufficiently for all the olives to be pressed at a time when the larvae of the last generation, which would be preserved in the olives that are left, or in the earth, according to the climate, are still in the fruit. If a first operation were not sufficient to destroy them all, it should be repeated the following year. The sacrifice entailed by this practice would be amply compensated by a succession of good crops and the certainty of a sure and permanent profit. In fact, by an early gathering at least half a crop of oil is still obtained ; whereas, by waiting for the usual period of gathering the olives, sufficient time is left for the larvae of the Dacus to devour their parenchyma, which deprives them of the little oil that they might have yielded if their destruction had been accomplished earlier. This early gathering has the advantage of causing the destruction of a great number of larvae, which will be so much towards diminishing the means of reproduction of the fly. III. HEMIPTERA. THE Hemiptera are particularly distinguished from other kinds of insects by the form of their mouth, which consists of a beak, more or less long, composed of six parts : that is, of a lower lip, or sheath ; four internal threads, representing the mandibles and jaws of the grinding insects, and which are the perforating parts of the beaks ; and, lastly, of the upper lip or labrum. Owing to this apparatus, these insects are essentially sucking ones, and chiefly nourish them- selves with the juices of vegetables, which they draw up with their beak. The wings of the Hemiptera are usually four in number ; in some species they are membranous and similar to each other, and in others the upper are of rather harder consistency than the lower ones. In general, the former are quite different from the lower wings, and are only membranous at the tip, whereas the other part is thick, tough, and coriaceous. The Hemiptera are divided into two very distinct sections. The one is composed of insects whose beak grows from the forehead or upper part of the head, and whose anterior wings are half coriaceous and half membranous, having the base of a different texture from the extremity : these are the Heteroptera (erepos, different ; -rrtpov, wing). The other section is composed of those whose beak grows from the lower part of the head, and whose anterior wings are always of the same consistency throughout : these are the Homoptera (6f*os, the same ; irWpov, wing). We are about to give the history of these two sub-orders. HETEROPTERA. The insects formerly known by the general name of Bugs have been divided by Latreille into two large families, containing : the one the Geocorisa* or Land Bugs ; the other the Plydrocoris(K,\ or Water Bugs. * From y4, the earth, and ic6pis, a. bug. t From SSwp, water, and Kopis, a bug. HEMIPTERA. 9 1 The land bugs consist of a great number of kinds, which, for the most part, are of little interest. We will only mention here the Penuftomiifa) commonly known as Wood Bugs; the Lygcei, Bugs, properly so called ; the Reduvii, and the Hydrometra. The Penfatomtdce, which comprise many genera, include the wood bugs of most authors. They are to be found on plants and trees. They fly quickly, but only for a short time. The Ornamented Pentatoma (Strachia \Pentatomd\ ornata), known as the Red Cabbage Bug, is very commonly found on the cabbage, and on most of the cruciferous plants. It is variegated with red and black, and its colours are subject to numerous variations. The Grey Pentatoma (Raphigaster griseus], Fig. 69, is common throughout the whole of Europe. In autumn these bugs are fre- quently to be found on raspberries, to which they impart their disagreeable smell. They are also to be found in quantities on the mullein, when that plant is in flower. The upper parts of the head are of a greyish brown, and are sometimes slightly purple. The coriaceous part of the hemelytra is of a purple tint, but the membranous part is brown. All these parts are covered with black spots, which are only to be seen with a magnifying-glass. The wings are blackish. The under part of the whole body and the feet are of a light and rather yellowish grey, with a considerable number of small black spots. The abdomen is black above ; and it is bordered with alternate black and white spots. We have repeated here the description given of this bug by the illustrious Swedish naturalist, De Geer, because our young readers have most likely met with this insect, or will do so some day when gathering raspberries. The Grey Pentatoma, marked with black, yellow, and red, is to be found throughout the whole of Europe in cultivated fields and gardens, sometimes also on the trunks of large trees, . especially elms. This species, in common with the greater part of those which compose the group we are describing, emits a smell when irritated or menaced by some danger. At other times no odour will be noticed. Let us hear what M. Le'on Dufour says on this subject " Seize the Pentatoma with a pair of pincers and plunge it into a glass of clear water ; look through a magnifying-glass, and you will see innumerable small globules arising from its body, which, bursting on the surface of the water, exhale that odour which is so disagreeable. This vapour, which is essentially acrid, if it happens 92 THE INSECT WORLD. to touch the eyes, causes a considerable amount of irritation. If one of these insects is held between the fingers, so as not to stop up the odoriferous orifices, and to cause this vapour to touch a part of the skin, a spot, either brown or livid, will ensue on that part, which lotions, though repeatedly applied, will at first fail to remove, and which produces in the cutaneous tissue an alteration similar to that which succeeds the application of mineral acids." The disagreeable smell exhaled by different species of Pentatoma is the result of a fluid secreted by a single pear-shaped gland, either red or yellow, which occupies the centre of the thorax, and which terminates between the hind legs. With the Syromasfes, which are bugs of this same section, the secretion has, on the contrary, an agreeable smell, which reminds one of that of apples. Many kinds of Pentatoma are destructive to agriculture. Others, however, attack the destructive insects, and ought therefore to be carefully spared. We will mention in this case the Blue Pentatoma, which kills the Africa* of the vine. There may be observed, at the foot and about the lower part of trees, or at the base of walls exposed to the mid-day sun, groups of fifty or sixty small insects pressed close to each other, and often one on the top of the other, their heads in the direction of a centre point. They are red, spotted with black. In the neighbourhood of Paris the children call them " Suisses," probably on account of the red on their bodies, that being the colour of the uniform of the Swiss troops formerly in the service of France. In Burgundy the children call them "pefits cochons rouges." They will be found described in Geoffrey's " Histoire des Insectes," under the name of the Red Garden Bug. At the present day they are placed in the genus Lygieus.\ When the bad weather comes, these little " Suisses " take refuge under stones and the bark of trees to pass the winter. During the whole of that season they remain in a sort of torpid state. But in the first days of spring they revive, and resume their ordinary habits. They suck the sap of vegetables, piercing the capsules of divers kinds of mallows, and always keeping in the sunshine. The Bug, popularly so called, or Bed Bug (Acanthia lectularia, or Cimex lectularius, Fig. 70), a most disagreeable and stinking insect, abounds in dirty houses, principally in towns, and above all in those of warm countries. It lives in beds, in wood- work, and paper- hangings. There is no crack, however narrow it may be, into which it is unable to slip. It is nocturnal, shunning the light. "Nocturnum * This species is Lyganus militaris.Ev. f A genus of beetles. HEMIPTERA. 93 fcetidum animal," says Linnaeus. Its body is oval, about the fifth of an inch in length, flat, soft, of a brown colour, and covered with little hairs. Its head is provided with two hairy antennae, and two round black eyes, and has a short beak, curved directly under its thorax, and lying in a shallow groove when the animal is at rest. This beak, composed of three joints, contains four thin, straight, and sharp hairs. The thorax is dilated at the sides. The abdomen is very much developed, orbicular, composed of eight segments, very much depressed, and easily crushed by the fingers. The hemelytra are rudimentary. It has no membranous wings. The tarsi have three articulations, of which the last is provided with two strong hooks. " These animals," says Moquin-Tandon, in his " Zoologie Medicale," " do not draw up the sanguineous fluid by suction, properly so-called, as leeches do. The organisation of their buccal apparatus does not allow of this. The hairs of the beak applied the one against the other exercise a sort of alternate motion, which draws the blood up into the oesophagus, very much in the same manner as water rises in a chain pump. This rising is assisted by the viscous nature of the fluid, and above all, by the globules it contains." The part of the skin which *the Bug has pierced, producing a painful sensation, is easily recognised by a little reddish mark, presenting in its centre a dark spot. Generally a little blister rises on the point pierced, and sometimes, if the Bug-bites are numerous, these blisters become confluent, and resemble a sort of eruption. These disgusting insects lay, towards the month of May, oblong whitish eggs (Fig. 7 1 ), having a small aperture, through which the larva comes out. The larva differs from the insect in its perfect state, in its colour, which is pale or yellowish. This insect exists in nearly the whole of Europe, although it is rare or almost unknown in the northern parts. The towns of central Europe are the most infested by this parasite, but those of the north are not completely free from its presence. The Marquis de Custine assures us that at St. Petersburg he found them numerous. It is found also in Scotland ; is very rare in the south of Europe ; and seldom seen in Italy, where it is, however, replaced by other insects more dangerous or more annoying. Fig. 70. Bed Bug (Acant/tia lectularia) magnified. Fig. 71. Egg of Bug, magnified. 94 THE INSECT WORLD. It has been said that the Bug was brought into Europe from America ; but Aristotle, Pliny, and Dioscorides mention its existence. It is certain that it was unknown in England till the beginning of the sixteenth century. A celebrated traveller, a Spanish naturalist, Azara, has remarked that the Bug does not infest man in his savage state, but only when congregated together in a state of civilisation, and in houses, as in Europe. From this he concluded that the Bug was not created till long after man, when, after many centuries had elapsed since his appearance on the globe, men formed themselves into societies, into republics, or little states. The bug is not a gluttonous insect, always bloodthirsty ; on the contrary, its sobriety is remarkable. It is only after a prolonged fast that it bites animals ; and Audouin has stated that it can live a year and even two years without food. From time immemorial a number of different means have been employed for destroying these insects ; but in spite of all, nothing is more difficult than to get rid of them from wood-work and paper- hangings, when they have once infested them. In general, strong odours cause their death. And so, to rid oneself of these disagreeable guests, it has been recommended to use tobacco smoke, essence of turpentine, the fumes of sulphur, &c. Mercurial ointment and corrosive sublimate are also excellent means for their destruction ; and for the same purpose the merits of a plant belonging to the order Cruciferae, Lepidium ruderale, have been much vaunted ; and more recently still, the root of the Pyrethrum, a species of camomile, reduced to powder, and blown into the furniture or wood-work. This powder is known and employed at Paris under the name of " poudre insecticide." There are two other kinds of bugs (Acanthia) which attack men. The one is the Acanthia d/iafa, which has been found in the houses of Kazan, and which differs from the bed bug not only in its form, but also in its habits. It does not live in companies, in the narrow cracks of furniture, but moves about alone, at a slow pace, over walls or the counterpanes of beds. Its beak is very long, and its bite is very painful, and produces obstinate swellings. The other species is the Acanthia rotundata, which is found in the Island of La Reunion, and attacks men in the same way as does the European bug. Two species of the same genus live as parasites on swallows and domestic pigeons. There is another species, which is peculiar to the bats of our climates. The Reduvius personatus, called also Fly Bug, by Geoffroy, the old historian of the insects of the environs of Paris, is common HEMIPTERA. 95 enough in France. It keeps to the houses, and is found especially near ovens and chimney-pieces. It is about three-quarters of an inch in length, oblong, flat on its upper side, brownish, has horizontal hemelytra crossed over each other, and very fully developed wings, which serve for flight. Its head, narrow, supported by a well-defined neck, is provided with two composite and two simple eyes. It requires, no doubt, to see very clearly, as it flies by night. It should not be caught without great caution. If you desire to examine it closely, when, in the hottest part of the summer, it comes in the evening and flutters round the lights, you must be careful how you seize it, for it wounds. The wounds inflicted by it are very painful more painful than those of the bee and they immediately cause a numbness. As the Reduvius kills different insects very rapidly, by piercing them with its long beak, it is probable that it secretes some kind of venom. But as yet the organ that produces this poison has not been discovered. However that may be, its beak is curved, and about the tenth of an inch long, the surface bristling with hairs. It is composed of three joints, and contains four stiff, lanceolate, and very pointed squamose hairs. This insect often seeks its prey in places where spiders spin their webs. When they walk on, or are caught in, the spiders' webs, the spiders take care not to seize them, for they fear their beak. They prudently allow them to struggle about the nets, where they very soon die of hunger. The Rediivius is often seen, either a prisoner or dead, in the midst of a spider's web. " This bug," says Charles de Geer, " has, in the pupal condition, or before its wings are developed, an appearance altogether hideous and revolting. One would take it, at the first glance, for one of the ugliest of spiders. That which above all renders it so disagreeable to the sight is that it is entirely covered, and, as it were, enveloped with a greyish matter, which is nothing else but the dust which one sees in the corners of badly-swept rooms, and which is generally mixed with sand and particles of wool, or silk, or other similar matters which come from furniture and clothes, rendering the legs of this insect thick and deformed, and giving to its whole body a very singular appearance." What instincts ! what habits ! Under this borrowed costume, under this cloak, which is no part of itself, the insect, as it were, masked, has become twice its real size. What becomes of its disguise, and how does it manage to walk ? Of what use to it is this dirty and grotesque fancy dress ? 96 THE INSECT WORLD. Let us listen to De Geer. " It walks as fast, when it likes, as other bugs ; but generally its walk is slow, and it moves with measured steps. After having taken one step forward, it stops a while, and then takes another, leaving, at each movement, the opposite leg in repose ; it goes on thus continually, step after step in succession, which gives it the appearance of walking as if by jerks, and in measure. It makes almost the same sort of movement with its antennae, which it moves also at intervals and by jerks. All these movements have a more singular appearance than it is possible for us to describe."* By means of this disguise, it can approach little animals, which become its prey, such as flies, spiders, bed bugs. Fig. 72. Pupa of Reduvius personatus, covered Fig. 73. Pupa of Reduvius personatus. denuded with its cloak of dust (magnified). of its cloak of dust (magnified). To see what a curious appearance the Reduvius presents, one should take off its borrowed costume. Then you will observe an entirely different animal, and one which has nothing repulsive about it. With the exception of the hemelytra and wings, which it has not yet got, all its parts have the form which they are to have later, after the wings are developed. Fig. 72 represents, from Charles de Geer's Memoir, the pupa of the Reduvius personatns covered with dust, and resembling a spider ; Fig. 73 the same insect cleaned, freed from the cloak of dust which served to disguise it. The Hydrometra (from SStap, water, and M T P"> to measure) * "Memoires pour servir & 1'Histoire des Insectes." Tome iii., p. 283. 410. Stockholm, 1773. I1EMIPTERA. 97 Fig. 74. Hydrometra stagnorum. have linear bodies. The head, which forms nearly the third of the entire length, is furnished with two long antennae, and armed with a thin, hair-like beak. The legs are long, and of equal length. The reader may have often seen the Hydrometra stagnorum walking by jerks on the surface of the water (Fig. 74). The body and legs tare of a fer- ruginous colour, the hem elytra a dull brown, and the wings hyaline, or glassy, and slightly blackish. Geoffrey says that it resembles a long needle, and calls it the Needle Bug. The Hydrocorisa, or Water Bugs, have the antennae shorter than the head, or scarcely at- taining to its length, and inserted and hidden under the eyes, which are in general of remarkable size. All these Hemiptera are aquatic and carnivorous. We will mention the two principal types, the Nepce, or Water Scorpions, and the Notonecta, or Boatmen. The Nepa cinerea (Fig. 75), which Geoffroy calls the Oval-bodied Water Scorpion, and which he also designates by the name of the Water Spider, is very common in the stagnant waters of ponds and ditches. Its body, oval, very flat, of an ashy colour, with red on the abdomen, is four-fifths of an inch long. The hemelytra are horizontal, coriaceous, and of a dirty grey colour. Its front legs, with short haunches, and very broad thighs, are terminated by strong pincers, which give to the insect a strong resem- blance to the scorpion. It is by folding back the leg and the tarsus under the thigh, that the animal holds its prey, and sucks it with its rostrum or beak. This rostrum is composed of three joints, and contains four pointed bristles. Two present on one side a sort of narrow sharp blade, and have teeth towards their base. Of the two others, the one* is a thin smooth needle, the other is provided with Fig. 75--Ne P a cinerea. hairs directed backwards and forwards. It is with this rostrum, which resembles a case of surgical instru- ments, that the Nepa pierces and sucks little aquatic insects, not even sparing its own species. Its wound is painful to man, but not in the least dangerous. With its four hind legs the Nepa swims, but at a very slow pace. It generally drags itself along the bottom of the 98 THE INSECT WORLD. water, on the mud, and does not avoid the hand put out to seize it. Its body is terminated by a tail, composed of t\vo grooved threads, which, when applied together, form a tube, capable of being moved from side to side. Through this canal it breathes the outer air ; it puts the end of it out of the water, and the air enters it by inspiration. Some very small hairs, with which the interiors of the grooves are lined, interlace each other, and prevent the water from penetrating into the canal. It is probable that this same canal serves also for depositing the eggs. These last resemble small seeds, covered with points, and are buried in the stalks of aquatic plants. Next to the Nepa comes the Ranatra, with a cylindrical, elon- gated, linear body, with very long and very thin hind legs, and of which one species, which Geoffroy calls the "aquatic scorpion with an elongated body," is common every- where in stagnant waters in spring. It is brownish, carnivorous, and very voracious. We must now mention the genus Corixa, of which one species, the Corixa striata, is very common. This insect walks badly and slowly on land, but swims and cuts through the water with a prodigious rapidity. Fig. 7 6. Corixa striata. However, it is not to delay over this last species that we have here mentioned the name of this genus. Some insects which belong to it, and which are found in Mexico, deserve to be alluded to, on account of certain peculiarities which their eggs present. A natu- ralist, M. Virlet d'Aoust, has published the following details on this subject : " Thousands of small amphibious flies," he says, " flit about in the air on the surface of lakes, and diving down into the water many feet, and even many fathoms, go to the bottom to lay their eggs, and only emerge from the water probably to die close by. We were fortunate enough to be present at a great fishing or harvest of the eggs, which, under the Mexican name of haiitle (liaoutle), serve for food to the Indians, who seem to be no less fond of them than the Chinese are of their swallows' nests, which they resemble somewhat in taste ; only the hautle is far from commariding such high prices as the Chinese pay for their birds' nests, which for that reason are reserved entirely for the tables of the rich ; while, for a few small HEM1PTERA, 99 coins, we were able to carry away with us about a bushel of the hautle, a portion of which, at our request, Mme. B was kind enough to prepare for us. " They dress these in different ways, but generally make a sort of cake, which is served up with a sauce, to which the Mexicans give a zest, as they do indeed to all their dishes, by adding to it chilie, which is composed of green pimento crushed. This is how the natives proceed when they are fishing for hautle: they form with reeds bent together a sort of fasces, which they place vertically in the lake at some distance from the bank, and as these are bound together by one of the reeds, the ends of which are so arranged as to form an indicating buoy, it is easy to draw them out at will. Twelve to fifteen days suffice for each reed in these fasces to be entirely covered with eggs, which they thus fish up by millions. The former are then left to dry in the sun, on a cloth, for an hour or more ; the grains are then easily detached. After this operation, they are replaced in the water for the next hautle harvest." M. Virlet had attributed to flies the eggs of which we have been speaking. But in 1851 M. Gue'rin-Meneville having received, transmitted to him by M. Ghiliani, eggs of which hautle is made, and some of the insects said to produce them, stated that the latter belonged to two different species. The one had been known a long time since under the name of Corixa mercenaria; M. Guerin- Meneville called the other Corixa femorata. The same entomologist discovered, among the eggs of these two species, other eggs of a more considerable size, and which he attri- buted to a new species of the genus Notonecta, about which we are now going to say a few words. The Notonecta glaiica, which Geoffroy calls the Large Bug with Oars (" Grande punaise a avirons "), is very common in ditches, reservoirs, and stagnant waters. Its body is oblong, narrow, con- tracted posteriorly, convex above, flat below, having, at its sides and its extremities, hairs which, when spread out, support the animal on the water. Its head is large and of a slightly greenish grey, and has on each of its sides a very large eye of a pale brown colour. Its thorax is greyish, the hemelytra of a greenish grey, the membranous wings white. Of its legs, the front four are short ; but the hind legs, almost twice as long, are furnished with long hairs, and resemble oars. It is with the aid of these that the animal moves through the water ; and it does so in a singular manner, placing itself on its back, and generally in an inclined position, as in Fig. 77. When this insect, on the contrary, drags itself along on the mud, H 2 IOO THE INSECT WORLD. the front legs are those which it employs, the hind legs being idle, and merely drawn along behind it. It is generally towards the evening or during the night that it comes out of the water, to walk and to fly, if it wishes to pass from one marsh to another. This bloodthirsty insect lives entirely by rapine it is one of the most carnivorous of insects. Those which it attacks die very soon after they have been hurt by it. De Geer thinks that the water bug drops into the wound a poisonous humour. It seizes upon insects much bigger, and apparently much stronger, than itself, and does not spare its own species. Fig. 77. Notonecta giauca. The instrument with which the Notonecta attacks its prey is composed of a very strong and very long conical beak, formed of four joints. The sucker is composed of an upper piece, short and pointed, and of four fine pointed hairs. The female of the Notonecta giauca lays a great number of eggs, white, and of elongated shape, which it deposits on the stems and leaves of aquatic plants. The eggs are hatched at the beginning of spring, or in May, and the young ones at once begin to swim about like their mother, on their backs, belly upwards. M. Leon Dufour says on this subject : "A dorsal region, raised like a donkey's back, or like the rounded keel of a boat, and covered with a. velvety substance, which renders it impermeable, numerous fine fringes which garnish either the hind legs, or the borders of the abdomen and thorax, or lastly in a double row form a crest or comb running down the surface of the belly, and which spread themselves out or fold themselves in at the will of the insect, just like fins, favour both this supine attitude and the accuracy of the swimming movements of the Notonecta. Since Nature which seems often to delight in producing extraordinary exceptions to her ordinary rules, thus bearing witness to the immensity of her resources had condemned this animal to pass its life in an inverted position, it was necessary, for the maintenance of its existence, that it should provide it with an organisation in harmony with this attitude. It is also for this object that its head is bent over its chest ; that its eyes, of an oval shape, can see below from above ; that the front as well as the middle legs, agile and curved, solely destined for prehension, can HEMfPTERA. IOI to a certain extent become unbent by means of the elongated haunches which fix them to the body, and clutch firm hold of their prey with the strong claws which terminate the tarsi." HOMOPTERA. We come now to the second group of the order Hemiptera, namely, Homoptera. The insects which compose this division, are numerous. They may be arranged into three great families, of the most remarkable members of which we shall give some account. These are the Cicadff, the Aphides or Plant Lice, and the Coccidce. The Cicada is the type of the first of these families. It has a deafening and monotonous song ; as Bilboquet says, in the " Saltim- banques," "those who like that note have enough of it for their money." Virgil pronounced a just criticism on the song of the Cicada : he saw in it nothing better than a hoarse and disagreeable sound : " At mecum raucis, tua dum vestigia lustro, Sole sub ardenti resonant arbusta cicadis," says the Latin poet in his " Eclogues," and repeats the same opinion in a verse in his " Georgics : " " Et cantu querulte rumpent arbusta cicadoe." The song of the Cicada, so sharp, so discordant, was, however, the delight of the Greeks. Listen to Plato in the first lines of " Phsedo : " " By Hera," cries the philosopher-poet, " what a charming place for repose ! . . . . It might well be consecrated to some nymphs and to the river Achelou, to judge by these figures and statues. Taste a little the good air one breathes. How charming, how sweet ! One hears as a summer noise an harmonious murmur accompanying the chorus of the Cicada." The Greeks, then, had quite a peculiar taste for the song of the Cicada. They liked to hear its screeching notes, sharp as a point of steel. To enjoy it quite at their ease they shut them up in open wicker-work cages, pretty much in the same way as children shut up the cricket, so as to hear its joyous cri-cri. They carried their love for this insect with the screaming voice so far as to make it the symbol of music. We see, in drawings emblematical of the musical art, a Cicada resting on strings of a cythera. A Grecian legend IO2 THE INSECT WORLD. relates that one day two cythera players, Eunomos and Aristo, con- tending on this sonorous instrument, one of the strings of the former's cythera having broken, a Cicada settled on it, and sang so well in place of the broken cord, that Eunomos gained the victory, thanks to this unexpected assistant. Anacreon composed an ode in honour of the Cicada. " Happy Cicada, that on the highest branches of the trees, having drank a little dew, singest like a queen ! Thy realm is- all thou seest in the fields, all which grows in the forests. Thou art beloved by the labourer ; no one harms thee ; the mortals respect thee as the sweet harbinger of summer. Thou art cherished by the muses, cherished by Phoebus himself, who has given thee thy har- monious song. Old age does not oppress thee. O good little animal, sprung from the bosom of the earth, loving song, free from suffering, that hast neither blood nor flesh, what is there prevents thee from being a god ?" It was in virtue of the false ideas of the Greeks on natural history in general, and on the Cicada in particular, that this little animal symbolised, among the Athenians, nobility of race. They imagined that the Cicada was formed at the expense of the earth, and in its bosom, on which account those who pretended to an ancient and high origin, wore in their hair a golden Cicada. The Locrians had on their coins the image of a Cicada. This is the origin which fable assigns to the custom : The bank of the river upon which Locris was built was covered with screeching legions of Cicadas ; whereas they were never heard (so says the legend) on the opposite bank, on which stood the town Rhegium. In explanation of this circumstance, they pretend that Hercules, wishing one day to sleep on this bank, was so tormented by the "sweet eloquence" of the Cicadas, that, furious at their concert, he asked of the gods that they should never sing there for evermore, and his prayer was immediately granted ! This is why the Locrians adopted the Cicada as the arms of their city. The Greeks did not only delight, as poets and musicians, in the song of the Cicada ; they were not content with addressing to it poems, with adoring it, and striking medals bearing its image ; obedient to their grosser appetites, they ate it. They thus satisfied at the same time both the mind, the spirit, and the body. The Cicadas are easily to be recognised by their heavy, very robust, and rather thick-set bodies, by their broad head, unprolonged, having very large and prominent ocelli, or simple eyes, three in number, arranged in a triangle on the top of the forehead, and short antennae. The immature anterior and posterior wings have the HEMIPTERA. 1 03 shape of a sheath, or case, enveloping the body when the insect is at rest ; these are transparent and destitute of colour, or sometimes adorned with bright and varied hues. The legs are not in the least suited for jumping. The female is provided with an auger, with which she makes holes in the bark of trees in which to lay her eggs. The male (Fig. 78) is provided with an organ, not of song, but of stridulation or screeching, which is very rudimen- tary in the female. We will stop a moment to consider the apparatus for producing the song, or rather the noise, of the male Cicada, and the structure of the female's auger. We are indebted to Reaumur for the discovery of the mechanism by the aid of which the Cicada produces the sharp noise which announces its whereabouts from afar. We will give a summary of the celebrated Memoir in which the French naturalist has so admirably described the musical apparatus of the Cicada.* It is not in the throat that the Cicada's organ of sound is placed, but on the abdomen. On examining the abdomen of the male of a large species of Cicada, one remarks on it two horny plates, of pretty good size, which are not found on the females. Each plate has one side straight ; the rest of its outline is rounded. It is by the Fig. 7 8.-cicada (Male). side which is rectilinear that the plate is fixed immediately underneath the third pair of legs. It can be slightly raised, with an effort, by two spine-like processes, each of which presses upon one of the plates, and when it is raised, prevents it from being raised too much, and causes it to fall back again immediately. If the two plates are removed and turned over on the thorax, and the parts which they hide laid bare, one is struck by the appearance which is presented. " One cannot doubt that all one sees has been made to enable the Cicada to sing," says Reaumur. " When one compares the parts which have been arranged so that it may be able to sing, as we may say, from its belly, with the organs of our throat, one finds that ours have not been made with more care than those by means of which the Cicada gives forth sounds which are not always agreeable." We here perceive a cavity in the anterior portion of the abdomen and which is divided into two principal cells by a horny triangle. tome 4to. IO4 THE INSECT \VORLD. " The bottom of each cell offtrs to children who catch the Cicada a spectacle which amuses them, and which may be admired by men who know how to make the best use of their reason. The children think they see a little mirror of the thinnest and most transparent glass, or that a little blade of the most beautiful talc is set in the bottom of each of these little cells. That which one might see if this were the case would in no way differ from what one actually sees ; the membrane which is stretched out at the bottom of the cells does not yield in transparency either to glass or to talc ; and if one looks at it obliquely, one sees in it all the beautiful colours of the rainbow. It seems as if the Cicada has two glazed windows through which one can see into the interior of its body." The horny triangle of which we spoke above only separates in two the lower part of the cavity. The upper part is filled by a white, thin, but strong membrane. This membrane is only drawn tight when the body of the Cicada is raised. But with all this, where is the organ of song ? What parts produce the sound ? Reaumur will enlighten us on this point. He opened the back of a Cicada, and laid bare the portion of the interior which corresponds with the cavity where the mirrors are, and was immediately struck with the size of the two muscles which meet and are attached to the back of the horny triangle, and to that one of its angles from which start the sides which form the cavities in which are both the mirrors. " Muscles of such strength, placed in the belly of the Cicada, and in that part of the belly in which they are found, seem to be only so placed in order that they may move quickly backwards and forwards those parts which, being set in motion, produce the noise or song. And indeed, whilst I was examining one of these muscles, in moving it about gently with a pin, slightly displacing it, and then letting it return to its proper place, it so happened that I made a Cicada that had been dead for many months sing. The song, as might be expected, was not loud ; but it was strong enough to lead me on to the discovery of the part to which it was due. I had only to follow the muscle I had been moving, to search for the part on which it abutted." In the large cavity, in which are the mirrors and the other parts mentioned above, there are besides two equal and similar compart- ments, two cells, in which are placed the instrument of sound. This is a membrane in the shape of a kettledrum, not smooth, but, on the contrary, crumpled and full of wrinkles (Fig. 79). When it is touched it is more sonorous than the driest parchment. If the furrows on its HEMIPTERA. IOJ convex surface are rubbed with a small body, such as a piece of rolled-up paper, incapable of piercing or tearing it, it is easily made to sound ; and the sound is occasioned by the portions of the kettle- drum which are depressed by the friction of the small body, returning to their former position as soon as it has ceased to act upon them. It is here that the two strong muscles act whose exis- tence and use were discovered by Reaumur. "It is clear," says this naturalist, "that when the muscle is alternately contracted and expanded with rapidity, one convex portion of the kettledrum will be rendered concave, and will then resume its convex form by the force of its own spring. Then this noise will be made, this song of which we have been so long seeking an explanation, because we wished to find out all the parts by means of which He, who never makes anything without its use, willed that it should be produced.'' Musica | Apparatus of the Let us add, to complete what we have already Male cicada, said on this subject, that if the kettledrums are .the essential organs of the insect's song, the mirrors, the white and wrinkled membranes, and the exterior shutters which cover in the whole apparatus, contribute largely, as Reaumur pointed out, to modify and strengthen the sound. We have said above that the female Cicada does not sing ; and so her singing organs are quite rudimentary. This fact, moreover, has been known for ages. Xenarchus, a poet of Rhodes, says, with little gallantry : " Happy Cicadas ! thy females are deprived of voice !" Nature has indemnified the female Cicada for this privation, by giving her an instrument less noisy indeed, but more useful. This is a sort of auger, destined to penetrate the bark of the branches of trees, and lodged in the last segment of the abdomen, which, for this purpose, is hollowed out groove-wise. By the aid of a system of muscles the auger can be protruded or retracted at pleasure. It is- furnished with three implements. In the middle there is a piercer, or bodkin, which when run into a branch supports the insect, and two stylets, whose upper edges, having teeth like a saw, resting back to back, on the middle implement, move up and down it. With this admirable instrument the female Cicada incises obliquely the bark and wood until she has almost reached the pith (Fig. So). The io6 THE INSECT WORLD. male sings while she is at work. When the cell is sufficiently deep and properly prepared, the female lays at the bottom of it from five to eight eggs. From these eggs come very small white grubs (Fig. 81), which leave their nest, descend by the trunk, and bury them- selves in the ground, where they devour the roots of the tree. They then become pupae, and hollowing out the earth with their front legs, which are very much developed, con- tinue to live at the expense of the roots. At the end of spring these pupae (Fig. 82) come out of the earth, hook themselves on to the trunks of trees, and strip themselves one fine evening of their skin, which remains whole and dried Very weak at first, these meta- morphosed insects drag them- selves along with difficulty. But next day, warmed by the first rays of the sun, having had, no doubt, time to reflect on their new social position, and less astonished than they were on the preceding evening, they agitate their wings, they fly, and the males send forth into the air the first notes of their screeching concert. The Cicadas remain on trees, whose sap they suck by means of their sharp-pointed beak. It is difficult enough to catch them, for owing to their large, highly-developed wings, they fly rapidly away on the slightest noise. They inhabit the south of Europe, the whole of Africa from north to south, America in the same latitudes as Europe, the whole of the centre and south of Asia, New Holland, and the islands of Oceania. The Cicada, which in hot climates always exposes itself to the ardour of the most scorching sun, is not found in temperate or cold regions. Fig. 80. Female Cicada laying her eggs in the groove she has bored in the branch of a tree. HEMIPTERA. IO/ The consequence is that the southern nations know it very well, whilst in the north the large grasshopper, which is so common in those regions, and whose song closely resembles that of the Cicada, is commonly taken for it. There was to be seen at the Exhibition of Fine Arts in 1866 a picture by M. Aussandon, " La Cigale et la Fourmi/' which showed, under an allegorical shape, the subject of La Fontaine's fable. The painter here represented the Cigale, or Cicada, under the form of a magnificent apple-green grasshopper. The artist Fig. Si. Larva of the Cicada. Fig. 82. Pupa of the Cicada. materialised here, as we may say, the common mistake of the inhabi- tants of the north, which makes them confound the Cicada with the great green grasshopper. For the rest, we may. by-the-by, say that La Fontaine's fable of " La Cigale et la Fourmi '' is full of errors in natural history. Nothing is easier than to prove the truth of this assertion. From the very first verses, the author shows that he has never observed the animal of which he speaks. "La Cigale ayant chante Tout 1'ete." No Cicada could sing " tout 1'ete," since it lives at the utmost for a few weeks only. " Se trouva fort depourvue Quand la bise fut venue." " Quand la bise fut venue " means without doubt the month of November or December. But at this season of the year the Cicada has a long time since passed from life to death. When one wanders along the outskirts of woods as early as the month of October, in the south of France, one finds the soil covered with dead Cicadas. La Fontaine's Cigale then could not have found itself " fort depourvue," for the simple reason that it was already dead. " Elle alia crier famine Chez la Fourmi, sa voisine, La priant de lui preter Quelque grain pour subsister." IO8 77/7: INSECT WORLD. The ant is carnivorous, and although it likes honey, it has nothing to do with grains of wheat, nor with any other grain, of which, according to the fabulist, it had laid up a stock. On the other hand, the Cicada, which he blames for having " Pas un seul petit morceau De mouche ou de vermisseau," never dreamt of such victuals, for it lives entirely on the sap of large vegetables. The fables of the poet, who is called in France, one never knows why, " Le bon La Fontaine," teem with errors of the same kind as those we have just pointed out. The habits of animals are nearly always represented as exactly the contrary to what they really are. To initiate himself into the mysteries of the habits of animals, La Fontaine certainly had neither the works of Buffon nor the memoirs of Reaumur, which had not then been written ; but had he not the book of Nature ? But it is time to mention the principal species of the Cicada. We will describe two : that of the Ash, which lives on those trees in the south of France ; and that of the Manna Ash, which is very common in the south-east of France. It is particularly plentiful in the forests of pines which abound between Bayonne and Bordeaux. It is on these two species of Cicada that Reaumur made the beautiful observations of which we gave a summary above. The Cicada plebeia or Tettigonia fraxini, very common in Pro- vence, is found, though rarely, in the forest of Fontainebleau, occasionally in La Brie. It is of a grey yellow below, black above ; the head and thorax are marked or striped with black. M. Solier, in a Memoir inserted in the " Annales de la Societe Ento- mologique de France," says that its song, very loud and very piercing, seems to consist of one single note, repeated with rapidity, which in- sensibly grows weaker after a certain time, and terminates in a kind of whistle, which can be partly imitated by pronouncing the two con- sonants J/, and which resembles the noise of the air coming out of a .little opening in a compressed bladder. When the Cicada sings, it moves its abdomen violently, in such a manner as alternately to move it away from, and to bring it near to, the little covers of the sonorous cavities ; to this movement is added a slight trembling of the mesothorax. The same entomologist relates a very interesting observation made on this species of Cicada by his friend, M. Boyer, a chemist at Aix, and which he himself verified. The Cicadas, in general, are very timid, and fly away at the least noise. However, when a OBMIPTERA. ICQ Cicada is singing, one can approach it, whistling the while in a quavering manner, and imitating as nearly as possible, its cry, but in such a manner as to predominate over it The insect then descends a small space down the tree, as if to approach the whistler ; then it stops. But if one presents a stick to it, continuing to whistle, the Cicada settles on it and begins again to descend backwards. From time to time it stops, as if to listen. At last, attracted, and, as it were, fascinated by the harmony of the whistle, it comes to the observer himself. M. Boyer managed thus to make a Cicada, which continued to sing as long as he whistled in harmony with it, settle on his nose. Charmed by this concert, the insect seemed to have lost its natural timidity. The Cicada orni is of a greenish yellow, spotted wfth black. The abdomen is encircled by the same colours. The elytra and the wings are hyaline, or glassy, and their veins alternately yellow and brown. The legs are yellow throughout. The song of this species is hoarse, and cannot be heard at any great distance. M. Solier, in the work we quoted just now, says that the song of this Cicada is of a deeper intonation, but that it is quick and is sooner over. It does not terminate in the manner which characterises that of the other species. Next the genus Cicada comes Fulgora, whose type is the Fulgora Janternaria, or Lantern Fly (Fig. 83). Belonging to South America, these insects are above all remark- able and easy to recognise, by their very large elongated head, which nearly equals three-quarters of the rest of the body. This prolonga- tion is horizontal, vesiculous, enlarged to about the same breadth as the head, and presents above a very great gibbosity. The antennae are short, with a globular second articulation, and a small terminal hair. The species represented in Fig. 83 is yellow varied with black. The elytra are of a greenish yellow, sprinkled with black ; the wings, of the same colour, have at the extremity a large spot resembling an eye, which is surrounded by a brown circle very broad in front. It inhabits Guyana. This remarkable insect enjoys a great renown with the vulgar, by a peculiarity which might be called its speciality the property of shining by night or in the dark. Hence its name of Fulgora lanteniaria. The knowledge of the Fulgora lanteniaria has been spread and popularised in Europe by a celebrated book, which has for its title, "Metamorphoses des Insectes de Surinam." This book, which contains the result of patient study of the natural history of Dutch no THE INSECT WORLD. Guyana (Government of Surinam), was written and published in three languages, by a woman whose name this work has rendered immortal Mile. Sybille de Me'rian and who won the admiration and respect HEMIPTERA. Ill of her contemporaries by her love of the beauties of Nature, and her perseverance in making them known and admired. Sybille de Merian was born at Bale. Daughter, sister, and mother of celebrated engravers, herself an excellent flower-painter, she had worked a long time at Frankfort and at Nuremburg ; and had read with the greatest attention the " Theologie des Insectes,"* and with admiration Mal- pighi's book on the silkworm. Full of enth'usiasm for the study of natural history, she left Germany, to visit the magnificent collection of plants which were kept in the hot-houses of Holland, and made admirable reproductions of them with her pencil. This attentive study of the vegetable world suggested to her the idea, which soon became an ardent desire, of observing these marvels of Nature in those parts of the globe in which they display themselves with the greatest magnificence and splendour. At the age of fifty- four, Sybille de Me'rian set out for equatorial America. From the very first days of her arrival she hazarded her life, sometimes without a guide, in the swampy plains or burning valleys of Guyana. During the two years she sojourned in those dangerous parts, she made a large collection of drawings and paintings, which were destined to inaugurate in Europe the introduction of art into natural history. In the plates to her work, Sybille de Merian represents always the insects she wishes to describe under its three forms of larva, pupa, and perfect insect. With this drawing she gives another of the plants which serves the insect for food, as also of the animals which prey on it. Each plate is a little drama. Near the insect is seen the greedy lizard opening its dreadful mouth, or the ferocious spider watching for it. The short life of insects is shown here in its entirety, with its continual struggles, its infinite artifices, its rapid end, and all the episodes of its existence, for which life, as in the case of the moral man, is but a long and painful struggle. Such was the work, such was the noble devotion and the worthy career of Sybille de Merian. Let women, let young girls, who are martyrs to the ennui of a life devoid of occupation, peruse her beautiful books, and learn from it how much a woman may do with the time which is now either utterly unoccupied or only devoted to useless employments. To study Nature in any of its phases ought, it seems to us, to give more satisfaction to the soul, more strength to the mind, and cause more admiration of and gratitude to the supreme Author of Nature than doing a little embroidery. * " Theologie des Insectes, ou Demonstration des Perfections de Dieu dans tout ce qui concerne les Insectes, par Lesser, traduit en Fran9ais." La Haye, 1742. 112 THE INSECT WORLD. It is, as we have already said, in the work of Sybille de Me'rian, " Metamorphoses des Insectes de Surinam,'' that one finds mentioned, for the first time, the luminous properties of the Fulgora lanternaria. The author thus relates her observations, which were the result of chance : " Some Indians having one day brought me a great number of the Lantern Flies, I shut them up in a large box, not knowing then that they gave light at night. Hearing a noise, I sprang out of bed and had a candle brought. I very soon discovered that the noise proceeded from the box, which I hurriedly opened ; but, alarmed at seeing emerging from it a flame, or, to speak more correctly, as many flames as there were insects, I at first let it fall. Having recovered from my astonishment, or rather from my fright, I caught all my insects again, and admired this singular property of theirs." Since the time when Mile, de Merian visited Guyana, different travellers have said that they could not observe, as she did, this phosphorescent phenomenon. It is, then, probable that this pro- perty only exists in the male or female insect, and then only at cer- tain seasons. What a marvellous spectacle must the rich valleys of Guyana present, when, in the stillness of the night, the air is filled with living torches ; when, the Fulgorce flying about in space, the flashes of fire cross each other, go out and blaze up again, shine brightly and then die out, and present, on a calm evening, the appearance of those lightning flashes which are usually seen only in the midst of a tempest ! Let us now go on to another interesting insect of the order of which we are treating, the Aphrophora, without being frightened by its disagreeable name, for there are many other names we may give it if we choose among those by which it is popularly known. In the months of June and July one sees on nearly every tree, and on plants of the most different kinds, a sort' of -white froth, composed of air bubbles, deposited on the leaves and branches. It is produced by an insect which the peasants in France call Crachat de Coucou, or Ecume printaniere (spring froth), and which is called in England, Cuckoo's spittle. De Geer carefully studied the metamorphoses of this insect. The Aphrophora (from aepu, I bear or carry) is lodged in the froth of which we have just been speaking. It lives in it, only leaving it when it has its wings. De Geer wondered why this insect confines itself during the whole of its life in liquid, and concludes that the froth has the effect of protecting the insect from the burning heat of the sun. This covering seems also to pro- HEMIPTERA. 1 1 3 tect it from the attacks of carnivorous insects and spiders. On the other hand, its skin is without doubt so constituted that it would perspire too freely if it were exposed to the air, and the insect would very soon die dried up. Whatever explanation may be given of the necessity for this semi-aerial, semi-liquid medium, it is easy to verify the fact that the larva of the Aphrophora cannot live long out of its frothy envelope. If withdrawn from it, the volume of its body diminishes perceptibly, and the poor animal dies, like a fish taken out of its natural element. The insects which live in this froth are six-legged grubs (Fig. 84), which, when the froth is cleared from them, walk quickly enough on the stalks and leaves of plants. They are green, with the belly yellow. De Geer wished to know how they produced this singular froth, and found out in the following manner : He took one of them out of its frothy dwelling, wiped it dry with a camel's-hair pencil, and placed it on a young stalk, recently cut from the honeysuckle, which he put into water in a glass, in order to preserve its freshness, and this is what he observed :-- " It begins," says the Swedish naturalist, "by fixing itself on a certain part of the stalk, in which it inserts the end of its trunk, and remains thus for a long time in the same attitude, occupied in sucking and filling itself with the sap. Having then withdrawn its trunk, it remains there, or else places itself on a leaf, where, after different reiterated move- ments of its abdomen, which it raises or lowers and turns on all sides, one may see coming out of the hinder part of its body a little ball of liquid, which it causes to slip along, bending it under its body. Beginning the same movements again, it is not long in producing a second globule of liquid, filled with air like the first, which it places side by side with, and close to, the preceding one, and continues the same operation as long as there remains any sap in its body. It is very soon covered with a number of small globules, which, coming out of its body one after the other, tend towards the front part, aided in this by the movement of the abdomen. It is all these globules collected together which form a white and extremely- fine froth whose viscosity keeps the air shut up in the globules, and prevents its froth from easily evaporating. If the sap which the larva has drawn from the plant is exhausted before it feels itself suf- ficiently covered with froth, it begins to suck afresh, until it has got 114 THE INSECT WORLD. a new and sufficient quantity of froth, which it takes care to add to its first stock."* It is in the froth that the larvae change into pupae, and they do not leave their habitation to undergo their final metamorphosis. They have then, says De Geer, the art of causing the froth inside to evaporate and dry up, in such a manner as to form a space inside the mass of froth, in which their bodies are entirely free. The exterior froth forms a roof closed in on all sides, under which the insect lies quite dry. In this vaulted cell the pupa disengages itself little by little from its skin, which first splits up along the head, and then on the thorax. This opening is sufficiently large to enable it to come out of its envelope. It is in the month of September that these insects are particularly abundant, and then the trees and plants are covered with them. Sometimes the froth drips off, like a sort of small rain, from branches which are covered with it. Towards the autumn the females are pregnant. They are then so heavy that that they can hardly jump or fly. The males, on the contrary, make prodigious bounds ; they throw themselves forward to a distance of more than two yards. They are very difficult to catch, and still more difficult to find again when one has once let them escape. And so Swammerdam calls these insects Satiterelles-Puces (Flea- Grasshoppers), because they jump like fleas. All that we have said relates to the Aphro- phora spumaria, or Froghopper (Fig. 85), an insect common all over Europe, and which Fig. 8 S .-The Froghopper Geoffroy calls the Cigale bedeaude. (Aphrophara spumaria). " It is of a brown colour," says Geofiroy, " often rather greenish. Its head, its thorax, and its elytra, are finely dotted ; on these last one sees two white oblong spots. The lower part of the insect is light brown." f We will mention, as it belongs to the group with which we are now occupied, a noxious insect, lassus devastate, which since 1844 seems to have taken up its quarters in the commune of Saint Paul, in the department of the Basses- Alpes. It sucks the leaves and stalks of cereals, causing them to wither, and may be found even in winter on young corn, but principally in the spring. According to M. Gue'rin-Mdneville, its head is of an ochrey yellow, with the apex " Memoires pour servir a 1'Histoire des Insectes," tome iii. t " Histoire abrege"e des Insectes, dans laquelle ces animaux sont ranges dans un ordre methodique. In 410. Tome i., p. 416. An VII. de la Republique. HEMIPTERA. 11$ marked with black spots ; the forehead yellow, elongated, striped with black, as are the legs. The elytra are straw-coloured and spotted with brown. The wings are transparent, and slightly blackened at 1. Hypsauchenia balista. 2. Membracis foliata. Fig. 86. 3. Centrotus cornutus. 4. Umbonia Spinosa. 5. Bocydium globula 6. Cyphonia furcata: the extremities. This remarkable insect, which is not more than the twelfth of an inch in length, jumps and flies with great ease. A small brownish insect, whose strange appearance struck Geoffrey, the historian of the insects of the environs of Paris, may I 2 Il6 THE INSECT WORLD. be seen springing over the fern stalks and thistles, in the damp parts of most of the woods of Europe. Geoffroy calls this insect " le Petit Diable." " Le Petit Diable," he writes, " is of a dark blackish-brown. Its head is flat, projecting but slightly, and, as it were, bent downwards. Its thorax, which is rather broad, has two sharp horns, which terminate in pretty long points on the sides. In the middle of the thorax is a crest or comb, which, prolonged into a sort of sinuous and crooked horn, terminates in a very sharp point, reaching to within one quarter of the extremity of the wing-cases. These viz., the wing-cases are dark, with brown veins ; and the wings, shorter than their cases, are rather transparent. The insect jumps very well, and is not readily caught. * The Petit Diable of Geoffroy is the Centrotus cormitus of modern naturalists. This curious little insect belongs to a strange and re- markable group, whose thorax takes the most extraordinary and most varied forms, as may be seen in Fig. 86, which represents somewhat magnified, many of these insects. Nearly all inhabit Guyana, the Brazils, and Florida. We will now proceed to examine one of the most interesting groups of insects that of the Plant-lice. These insects have for a long time attracted the attention of naturalists. They are so abun- dant that all our readers have seen them, and there are few plants in our fields or gardens which do not nourish some species. How often does one hesitate in gathering a rose or a bit of honeysuckle, for fear of touching the unattractive guest of those charming flowers ! During the whole of the summer one sees on the branches, on the leaves, but principally on the young shoots of the rose-tree, large companies of green plant-lice, which subsist on the sap of the tree. Some are provided with wings (Figs. 87, 88), others are wingless (Figs. 89, 90). The last-named are the largest, and are a line and a half long. They are entirely green, except two parts, of which we will speak immediately. The body is oval ; the head is small, and furnished with two brown eyes. The skin is smooth, and tightly drawn over the body. The antennae, which are very long and slender, almost equal the body in length. The six legs are long and slim, and the short feet terminate in two hooks. On the upper part of the body are two small cylindrical horns, surmounted by a small knob. The antennae and these horns are black. The winged individuals are of the same size as these, but are of a " Histoire abregee ties Insectes, dans laquelle ces animaux sont ranges dans un ordre methodique. In 4(0. Tome i. , p. 423. An VII. de la Republique. HEMIPTERA. Ii; dark green colour, mixed with black. The wings are transparent, and the upper ones are as long again as the body. The young shoots of the elder-tree, all round their circumference for the length of from a foot to a foot and a half, are often covered with black plant- lice, or with those of a greenish-black colour. They are crowded one against the other, and sometimes there are two layers of them. Winged Aphides, or Plant-lice (magnified). If observed without moving the plant about, they appear to be tranquil and inactive. They are, however, then absorbing from the plant the nourishment it should have ; piercing with the point of their trunks the epidermis of the leaves or stalks, and drawing from them a nourishing liquid. But this occupation is confined to those which are on the plant itself. Those which, on account of the enormous agglomeration of Fig. 89, 9:1. Wingless Aphides, or Plant-lice (magnified). these insects, walk, not on the branch, but on other plant-lice, and cannot therefore suck the sap of the plant, are employed entirely in preserving and multiplying their species. Reaumur often saw the latter, easily recognised by their great size, giving birth to little plant-lice, which are quite alive when they leave their mother. The young ones set off and mount or descend till they reach one end of the crowd, and there each takes up its position, like a cardboard capuchin (capucin de carte), in such a manner Il8 THE INSECT WORLD. that the head is just behind the plant-louse which precedes it. There they bury their trunks in the vegetable tissue, and set to work to imbibe the sap. Small as is the trunk of the plant-louse, yet when there are thousands of those little beings fixed to the stalk or the leaves of a plant, it is evident that it must suffer. And so the plant-louse is, in truth, one of the most terrible enemies of our agricultural and horticultural productions, and the exact list of the ravages which it occasions would be indeed interminable. We will confine ourselves to a few examples. For some years the lime-tree aphis has seriously attacked the lime-trees of the public promenades of Paris. The peach-tree plant-louse causes the blight of the leaves of that tree. It is to these prolific little parasites that are due, in a great number of rases, the contortions of leaves and of the young shoots of trees of all sorts. These insatiable depredators cause sometimes a still more re- markable alteration. On the leaves of elms are often seen bladders round and rosy, like little apples. On opening these bladders one finds that they are inhabited by a species of aphis. On the black poplar galls of different kinds grow, some from the leaf stalks, and others from the young stems. They are rounded, oblong, horned, and twisted into a spiral. Other galls show themselves on the leaf itself. They are all inhabited by plant-lice, differing from those of which we have given a description above, in the extremity of their abdomen not presenting the two remarkable horns to which we shall have later to call the attention of the reader. The body is generally covered with a long and thick down. Of this genus, the species, alas ! so unfortunately celebrated is the Apple-tree Aphis (Myzoxyle mali\ which attacks that tree. This insect is of a dark russet brown, with the upper part of the abdomen covered with very long white down. Its presence was announced for the first time in England in 1789, and in France, in the department of the Cotes du Nord, in 1812. In 1818 it was found in Paris, in the garden of the Ecole de Pharmacie. It had become common in 1822 in the departments of the Seine, the Somme, and the Aisne. In 1827 its presence in Belgium was announced. The apple-tree aphis, according to M. Blot, can only exist on that tree. Carried away and placed on any other, it very soon perishes. It does not attack the blossom, the fruit, nor the leaves, but fixes itself on the lower part of the trunk, whence it propagates itself down- wards as far as the roots, underneath the graftings, &c. It also likes to lodge in cracks of the trunk and large branches. But it always HEMIPTERA. 1 19 looks out for a southern, and avoids a northern aspect. It is not active, walks very little, and its dissemination from one place to another can only be explained by the facility with which so small an insect can be transported by the wind, its lightness being still more increased by the down which covers it. The Myzoxyle mali renders the wood knotty, dry, hard, brittle, and brings on rapidly all the symptoms which characterise old age and decay in attacked trees. M. Blot recommends the following means for preserving the apple-tree from this insect : Employ for the seed-beds the pips of bitter apples only ; give to the nursery and to the plants only as much shelter as is absolutely necessary ; avoid those sites which are too low and too damp ; encourage the circulation of air, and the desiccation of the soil ; surround the foot of each apple-tree with a mixture of soot or of tobacco and fine sand. As for the manner of freeing a tree once invaded by this insect, the most simple plan is to rub the trunk and the branches, in order to crush the insects, or to employ a brush or broom. We spoke above of the reproduction of the aphis, but without entering into any particular details ; we mil now touch upon this question, one of the most interesting in natural history. It was at the time when Reaumur was writing his immortal " Histoire des Insectes,"when Trembley was publishing his admirable researches on the freshwater Hydra, whose wonderful vitality we have mentioned in our work on Zoophytes and Molluscs,* that another naturalist astonished the learned world by his experiments on the reproductions of plant lice. This naturalist, whose name will live quite as long as those of Reaumur and of Trembley, was Charles Bonnet, of Geneva. Charles Bonnet made the extraordinary discovery that aphides can increase and multiply without the intervention of the sexes. An isolated specimen can produce a series of generations of its kind. We will relate the curious experiments of the Genevese naturalist. He placed in a flower-pot, filled with mould, a phial full of water, and put into this phial a little branch of spindle, having only five or six leaves, and perfectly free from any insect. On one of these leaves he placed a plant-louse, which was born under his own eyes, of a wingless mother. He then covered the branch with a glass shade, whose rim fitted exactly into the top of the flower-pot. Having taken these precautions, Charles Bonnet was perfectly certain of being able to observe his prisoner at his ease. He could keep it under his * "The Ocean World." I2O THE INSECT WORLD. ye and under his hapd, with more certitude and security than was the mythological Danae, shut up, by order of Acrisius, in a tower of bronze. " I took care," says Charles Bonnet, " to keep a correct journal of the life of my insect. I noted down its least movements ; nothing it did seemed to me indifferent. Not only did I observe it every day from hour to hour, beginning generally at four or five o'clock in the morning, and only leaving off at about nine or ten at night ; but 1 even looked many times in the same hour, and always with the magnifying glass, to render my observation more exact, and to learn the most secret actions of my little lonely one. But if this continual application cost me some trouble, and bored me not a little, in amends I had some cause for self-applause and for having subjected myself to all this trouble My plant-louse changed its skin four times : on the 23rd, in the evening ; on the 26th, at two in the afternoon ; on the 29th, at seven o'clock in the morning ; and on the 3151, at about seven o'clock in the evening Happily delivered from these four illnesses through which it was obliged to pass, it at last reached that point to which, by my care, I had been trying to bring it. It had become a perfect plant-louse. On the ist of June, at about seven o'clock in the evening, I saw, with great satisfaction, that it had given birth to another ; from that time I thought I ought to look upon it as a female. From that day up to the 2oth inclusive, she produced ninety-five little ones, all alive and doing well, the greatest number of which were born under my own eyes !" * He very soon made some other experiments on the aphis of the elder-tree, so as to assure himself if the generations of plant-lice, reared successively in solitude, preserved the same property of pro- creating without copulation. "On the 1 2th of July," says he, "about three o'clock in the afternoon, I shut up a plant-louse that had just been born under my eyes. On the 2oth of the same month, at six o'clock in the morning, it had already produced three little ones. But I waited till the 2 2nd towards noon before I shut up a plant-louse of the second generation, because I could not manage earlier to be present at the birth of one of those produced by the mother I had condemned to live in solitude. I always continued to observe the same precaution. I shut up only those plant-lice which were born under my very eyes. A third * "Traite d'Insectologie, ou Observations sur les Pucerons," pp. 2838. ire partie, i8mo. Paris, 1745. HEMIPTERA. 121 generation began on the ist of August ; it was on this day that the plant-louse I had shut up on the 22nd of July gave birth to this genera- tion. On the 4th of August, about one o'clock in the afternoon, I put into solitary confinement a plant-louse of the third generation. On the ninth of the same month, at six in the evening, a fourth generation, due to this last one, had already seen the light : it had given birth to four little ones. On the same day, towards midnight, all intercourse with its own species was forbiden to the plant-louse of the fourth generation born at that hour. On the i8th, between six and seven o'clock in the morning, I found this last in the company of four little ones to which it had given birth." * In this case, the want of food caused the death of the isolated individual of the fifth generation, and the experiment was brought to a close. Bonnet then tried experiments on the plantain aphis, following them up during five consecutive generations, which succeeded each other without interruption, in the space of three months. After having stated the extraordinary facts, which he relates with the most perfect simplicity, Charles Bonnet, examining at the end of the fine season specimens of the winged oak-tree aphis, was able to be present at their nuptials. He preserved the females with great care, and saw, not without profound astonishment, that they gave birth, not to small living insects, as was the case in the first ex- periments, but to eggs of a reddish colour, which were stuck fast to each other, on the stem or stalk of the plant. A short time afterwards, this illustrious observer was able to convince himself that the oak-tree plant-lice, whose nuptials he had witnessed in the autumn, present the same phenomena of solitary and viviparous propagation, already so often mentioned by him. At last some new observations permitted him to establish beyond all doubt the connection of these facts, in appearance so contra- dictory. He discovered that, during the whole of the fine season, the plant-lice are solitary and viviparous, but that towards the autumn these creatures return to the ordinary course of things, and are propagated by eggs, whose development requires the co-operation of a male and female individual. These eggs are hatched in Spring, and produce only viviparous plant-lice. In the autumn the males and females show themselves, and from that moment ovipositing recommences. These curious facts, seen and published more than a century ago, have been verified many times since. * "Traite d'Insectologie,'' &c., pp. 67 69. 122 THE INSECT WORLD. In 1866 M. Balbiani asserted that the plant-lice are herma- phrodite, or of both sexes at the same time, which would explain the facts observed by Charles Bonnet. But the anatomical proofs appealed to by Balbiani in support of this idea are far from establish- ing the existence of this arrangement of sexes among them. The observations of Charles Bonnet produced profound astonishment among naturalists, and, in this respect, 1743 may be considered as a memorable year. The simple statement of the few experiments which he made, and which we have cited, has sufficed to show how rapid is the multipli- cation of aphides. A single female produced generally 90 young ones ; at the second generation these 90 produce 8, 100 ; these give a third generation, which amounts to 729,000 insects ; these, in their turn, become 65,610,000 ; the fifth generation, consisting of 590,490,000, will yield a progeny of 53,142,100,000; at the seventh, we shall thus have 4,782,789,000,000 ; and the eighth will give 441,461,010,000,000. This immense number increases immeasurably when there are eleven generations in the space of a year. Fortunately a great many carnivorous insects wage fierce war against the plant- lice, and destroy immense numbers of them. Thus they are kept in check, and prevented from multiplying inordinately. To show with what prodigious abundance the reproduction of these little but formidable parasites must go on, we will relate a fact which was made known to us by M. Morren, Professor in the University of Liege. The winter of 1833 34 had been extremely warm and dry; whole months had passed without any rain. A well-known savant, Van Mons, had foretold, as early as the i2th of May, that all the vegetables would be devoured by plant-lice. On the 28th of September, 1834, at the moment when the cholera had began to spread its ravages over Belgium, all ot a sudden a swarm of plant- lice showed themselves between Bruges and Ghent. They were to be seen the next day at Ghent, hovering about in troops, in such quantities that the daylight was obscured. Standing on the ramparts, one could no longer distinguish the walls of the houses in the town, so covered were they with plant lice. The whole road from Antwerp to Ghent was rendered black by innumerable legions of them. They appeared everywhere quite suddenly. People were obliged to protect their eyes with spectacles and their faces with handkerchiefs, to keep off the painful and disagreeable tickling caused by them. The progress of these insects was interrupted by mountains, hills, even by undulations of land of very slight elevation, but sufficient to have an influence on the wind. M. Morren thinks that they came from HEMIPTERA. 123 a great distance, and that they arrived in Belgium by the sea-coast. Whatever be the explanation of the phenomenon, it establishes sufficiently the prodigious multiplication of these little insects. There is another trait, and without doubt the most curious in the history of the aphides, to which we have still to call the attention of the reader : we mean the relations which exist between them and the ants. No one can have failed to observe ants frequenting those places where plant-lice are gathered together in great numbers. Are ants simply friends of the plant-lice, as thought the ancients ? or have their visits some selfish object ? Linnaeus, Bonnet, and Pierre Huber thought that the ants did not pay these visits for nothing, and that they had some object in view. But what could they want of the plant-lice ? It is to Pierre Huber we owe the solution of this mystery. This naturalist has made the most beautiful observations on the relations which exist between plant-lice and ants. They are detailed in a chapter of his admirable work, entitled " Recherches sur les Mceurs des Fourmis Indigenes." The plant-lice have, as we have said, at the extremity of their abdomen, two small movable horns. These are in communication with a little gland which produces a sugary liquid. When one care- fully observes plant-lice attached to the stem of a plant, one sees a little syrup droplet oozing out of the extremity of these tubes. M. Morren, who has made some interesting observations on the anatomy and generation of the aphis, says that, having shut up females in wide-mouthed glass bottles, he saw the young, a little time after their birth, suck the sweet juice which exudes from the little tubes at the extremity of the mother's abdomen. This secretion seems, then, destined for the nourishment of the young* in the first moments of their existence, before they are able to nourish them- selves on vegetable juices. The saccharine fluid produced by the mother must be, then, a sort of milk intended for the nourishment of her young. This being settled, attend to what follows. In all places where plant-lice are assembled in great numbers it is easy to observe how excessively fond ants are of the sugary liquid destined for suckling the young. But how do the ants manage to get the plant- lice to allow themselves to be, as we may say, milked ? " It had been already noticed," says this celebrated observer, " that the ants waited for the moment at which the plant-lice caused this precious manna to come out of their abdomen, which they immediately seized. But I discovered that this was the least of their talents, and that they also knew how to manage to be served with 124 THE INSECT WORLD. this liquid at will. This is their secret. A branch of a thistle was covered with brown ants and plant-lice. I observed the latter for some time, so as to discover, if possible, the moment when they caused this secretion to issue from their bodies ; but I remarked that it very rarely came out of its own accord, and that the plant-lice, which were at some distance from the ants, squirted it out with a movement resembling a kick. " How did it happen, then, that the ants wandering about on the thistle were nearly all remarkable for the size of their abdomens, and were evidently full of some liquid ? This I discovered by narrowly watching one ant, whose proceedings I am going to describe minutely. I saw it at first passing, without stopping, over some plant-lice, which did not seem in the least disturbed by its walking over them ; but it soon stopped close to one of the smallest, which it seemed to coax with its antennae, touching the extremity of its abdomen very rapidly, first with one of its antennae and then with the other. I saw with surprise the liquid come out of the body of the plant-louse, and the ant forthwith seize upon the droplet and convey it to its mouth. It then brought its antennas to bear upon another plant-louse, much larger than the first ; this one, caressed in the same manner, yielded the nourishing fluid from its body in a much larger dose. The ant advanced and took possession of it. It then passed to a third, which it cajoled as it had the preceding ones, giving it many little strokes with its antennae near the hinder extremity of its body ; the liquid came out immediately, and the ant picked it up A small number of these repasts are sufficient to satisfy the ant's appetite. (See Fig. 91.) " It does not appear that it is out of importunity that these insects obtain their nourishment from the plant-lice. " The neighbourhood of ants is agreeable to plant-lice, since those which could get out of the way of their visits, viz., the winged plant- lice, prefer to remain amongst them, and to lavish upon them the superabundance of their nourishment."* What we have just related applies not only to the brown (Formica brunnea), but also to the tawny ant (Formica flava], to the ashy black (Formica nigra\ to the fuliginous (Formka fuliginosd), and to a great many more. The Red Ant (Formica rnfa) is singularly adroit in seizing the droplet left it by the plant-louse. According to Pierre Huber, it * "Recherches sur les Moeurs des Fourmis Indigenes." pp. 181 186. 8vo. Paris, iSio. HEMIPTERA. 12$ employs its antennae, which swell somewhat towards their extremities, in conveying this droplet to its mouth, and causes it to enter it by pressing it first on one side, then on the other, using its antennas as if they were fingers. The greater number of ants seek them on those plants on which they usually fix themselves the lowest herbs, as well as the highest trees. There are some, however, which never leave their place of abode, and never go out to the chase. These are the little ants, of a pale yellow colour, rather transparent, and covered with hairs, and which are extremely numerous in our meadows and orchards. These subterranean creatures are very noxious to the farmer. Pierre Huber often wondered how they subsisted, and with what food they could provision themselves, without quitting their gloomy habitations. Having one day turned up the earth of which a habitation was composed, in order to discover if any treasure were to be found stowed away there, he found nothing but plant-lice. Of these the greater number were fixed to the roots of the trees which hung down from the roof of their subterranean nest ; others were wandering about among the ants. These latter, moreover, set about milking their nurses, as usual, and with the same success. To verify his discover)', he dug up a great number of nests of the yellow ant, and invariably found aphides in them. So as to study the relations which must exist between these insects, he shut up ants with their friends, the plant-lice, in a glazed box, placing at the bottom of the box, earth, mixed with the roots of some plants, whose branches vegetated outside the box. He watered this ant-hill from time to time, and thus both the animals and the plants found in his apparatus sufficient nourishment. " The ants," he says, " did not endeavour in the least to make their escape. They seemed to want for nothing, and to be quite content. They tended their larvae and females with the same affection they would have shown in their usual ant-hill ; they took great care of the plant-lice, and never did them any harm. These, on the other hand, did not seem to fear the ants ; they allowed themselves to be moved about from one place to another, and when they were set down they remained in the place chosen for them by their guardians. When the ants wished to move them to a fresh place, they began by caressing them with their antennas, as if to request them to abandon their roots or to withdraw their trunk from the cavity in which it was inserted ; then they took them gently above or below the abdomen with their jaws, and carried them with the same care they would have bestowed on the larvae of their own species. I saw the same ant take three plant-lice in succession, each 126 THE INSECT WORLD. bigger than itself, and carry them away into a dark place However, the ants do not always act so gently towards them. When they fear that they may be carried off by ants of another kind, and living near their habitation, or when one opens up too suddenly the turf under which they are hidden, they seize them up in haste and carry them off to the bottom of their little cavern. I have seen the ants of two different ant-hills fighting for their plant-lice. When those belonging to one ants' nest could enter the nest of the others, they took them away from their rightful owners, and often these took possession of them again in their turn ; for the ants know well the value of these little animals, which seem made on purpose for them, they are the ants' treasures. An ants' nest is more or less rich, according as it is more or less stocked with plant-lice. The plant- lice are its cattle, its cows, its goats. One would never have thought that the ants were a pastoral people ! "* Their hiding in the ants' nest is not voluntary ; they are prisoners of war. The ants, after having hollowed out galleries in the midst of roots, make a foray upon the turf, and seize upon plant-lice scattered about here and there, bringing them with them, and collect them together in their nests. The captive insects take their wrongs with patience, and behave like philosophers under this new kind of life. They lavish on their masters, with the best grace in the world, the nutritious juices with which their bodies superabound. Charles Bonnet has stated some real wonders of the cleverness and industry of other ants which also make a provision of plant-lice. " I discovered one day," says he, "a Euphorbia, which supported in the middle of its stem a small sphere, to which it served as the axis. It was a case which the ants had constructed of earth. They issued forth from this by a very narrow opening made in its base, descended the stem, and passed into a neighbouring ants' nest. I destroyed one part of this pavilion, built almost in the air, so that I might study the interior. It was a little room, the vault-shaped walls of which were smooth and even. The ants had profited by the form of the plant to sustain their edifice. The stalk passed up the centre of the apartment, and for its timber-work it had the leaves. This retreat contained a numerous family of plant-lice, to which the brown ants came peacefully, to make their harvest, sheltered from the rain, the sun, and from other ants. No insect could disturb them ; and the plant-lice were not exposed to the attacks of their numerous enemies. I admired this trait of industry ; and I was not * "Recherches," &c., pp. 192 194. HEMIPTERA. I2/ long in finding it again, in a more interesting character, in ants of different species. " Some red ants had built round the foot of a thistle a tube of earth, two inches and a half long by one and a half broad. The ants' nest was below, and communicated directly with the cylinder. I took the stalk, with what surrounded it, and all that the cylinder contained. That portion of the stem which was inside the earthen tube was covered with plant-lice. I very soon saw the ants coming out at the opening I had made at the base ; they were very much astonished to see daylight at that place, and I saw that they lived there with their larvae. They carried these with great haste to the highest part of the cylinder which had not been altered. In this retreat they were within reach of their plant-lice, and here they fed their young. " In other places many stalks of the Euphorbia laden with plant- lice rose in the very centre of an ant-hill belonging to the brown ants. These insects, profiting by the peculiar arrangement of the leaves of this plant, had constructed round each branch as many little elongated cases ; and it was here they came to get their food. Having destroyed one of these cells, the ants forthwith carried off into their nests their precious animals ; a few days afterwards it was repaired under my eyes by these insects, and the herd were taken back to their pens. " These cases are not always at a few inches from the ground. I saw one five feet above the soil, and this one deserves also to be described. It consisted of a blackish, rather short tube, which was built round a small branch of the poplar at the point where it left the trunk. The ants reached it by the interior of the tree, which was excavated, and without showing themselves, they were able to reach their plant-lice by an opening which they had made in the base of this branch. This tube was formed of rotten wood, of the vegetable earth of this very tree, and I saw many a time the ants bringing little bits in their mouths to repair the breaches I had made in their pavilion. These are not very common traits, and are not of the number of those which can be attributed to an habitual routine.'"'* One day, Pierre Huber discovered in a nest of yellow ants a cell containing a mass of eggs having the appearance of ebony. They were surrounded by a number of ants, which appeared to be guarding them, and endeavouring to carry them off. Huber took possession of the cell, its inhabitants, and of the * "Traite d'Insectologie," &c., pp. 198201. 128 THE INSECT WORLD. Fig. 91. Aphides and Ant (magnified). little treasure it contained, and placed the whole in a box lid, covered with a piece of glass, so as to be more easily observed. He saw the HEMIPTERA. 12$ ants approach the eggs, pass their tongues in between them, de- positing on them a liquid. They seemed to treat these eggs exactly as they would have treated those of their own species ; they felt them with their antennae, gathered them together, raised them frequently to their mouths, and did not leave them for an instant. They took them up, and turned them over, and after having examined them with care, they carried them with extreme delicacy into the little box of earth placed near them.* These were not, however, ants' eggs. They were the eggs of aphides. The young which were soon to be hatched were to give to the provident ants a reward for the attentions they had lavished upon them. How wonderful are the life and the habits of the plant-lice, and their relations to ants ! But we should be led on too far, if we were to pursue these attractive details. We pass on now to the history of another family namely, the Gallinsccta, as Re'aumur calls them, or Cocci. They pass the greatest part of their lives that is to say, many months entirely motionless, sticking to the stalks or branches of shrubs ; remaining thus as devoid of movement as the plant to which they are attached. One would say that they were part and parcel of it. Their form is so simple, that nothing in their exterior would make one guess them to be insects. The larger they become the less they resemble living things. When the coccus is in a state for multiplying its species, when it is engaged in laying its thousands of eggs, it resembles only an ex- crescence of the tree. The Gallinsecta are found on the elm, the oak, the lime, the alder, the holly, the orange-tree, and the oleander. Some of the species are remarkable for the beautiful red colouring matter which they furnish. Such are the Coccus cacti, the Chermes variegatus, or Oak Tree Cochineal, and the Coccus polonicus. The Common Cochineal, Coccus cacti, is found in Mexico, on the Nopal, or prickly pear (Opuntia), particularly on the Opuntia vulgaris, the Opuntia cocci/era, and the Opuntia una, plants which belong to the family of the Cactaceas. These insects are rather remarkable, in that the male and female are so unlike, that one would take them for animals of different genera. The male presents an elongated, depressed body, of a dark-brown red. Its head small, furnished with two long feathery antennas, has only a rudimentary beak. The abdomen is terminated by two fine * " Recherches," &c., pp. 205, 206. I3O THE INSECT WORLD. hairs, longer than its body. The wings, perfectly transparent, reach beyond the extremity of its abdomen, and cross each other horizontally over its back. It is lively and active. The female presents quite a different appearance. It is in the first place twice as large as the male (Fig. 92), convex above, flat below. It resembles a larva, and has no wings. Its body is formed of a dozen segments, covered with a glaucous dust. The beak is very fully developed, and the two hairs or bristles on the abdomen are much shorter than in the male. The weight of the body, combined with the shortness of the legs, prevents these creatures from being active. The legj only serve, in fact, for clinging to the vegetable from which they draw their nourishment. The circumstances attending the birth of the cochineal insect are very curious. The larvae are born in the dried-up body of their dead mother, the skeleton of their mother serving male and female. them as a cradle. This happens thus : The eggs are attached to the lower part of the mother's body. When the abdomen of the mother is empty, its lower side draws up towards the upper side, and the two together form a pretty large cavity. When the mother dies, which is not long in happening, her abdomen dries up, her skin becomes horny, and forms a sort of shell. It is in this membranous cradle that the larvae of the cochineal insect are born. The cochineal insect in its wild state lives in the woods. But it can without difficulty be reared artificially. Every one knows that the little insect called the cochineal, furnishes, when its body has been dried and reduced to powder, a colouring matter of a beautiful red, peculiar to itself. This circum- stance has ''saved the cochineal from the persecution to which so many other kinds of insects have been devoted by the hand of man. In hot climates, in which the cochineal insect delights, it has been preserved, and is cultivated as an article of commerce. This is how the cochineal is reared in Mexico : An open piece of land is chosen, protected against the west wind, and of about one or two acres in extent. This is surrounded with a hedge of reeds, planted in lines, distant from each other about a yard, with cuttings of cactus at most about two feet apart. The cactus garden made, the next thing is to establish in it cochineals. With this object in view they are sought in the woods, or else the females of the cochineal insect which are pregnant are taken off plants which have been sheltered jl i ill HEMIPTERA. 133 during the winter, and placed in dozens, in nests made of cocoa-nut fibres, or in little plaited baskets made of the leaves of the dwarf palm, and hung on the prickles of the cactus. These are very soon covered with young larvae. The only thing now required to be done is to shelter them from wind and rain. (Plate IV.) The larvae are changed into perfect insects, which take up their abode permanently on the branches of the cacti, as Fig. 93 repre^ sents. The Mexicans gather them as soon as they have reached the perfect state. The harvest cannot be difficult, considering the immobility of these little creatures. When collected, the cochineals are killed, packed in wooden boxes, and sent to Europe, to be used in dyeing. Such is the method, very simple, as we see, of rearing the cochi- neal a method which has been followed for centuries in Mexico. Towards the end of the year 1700, a Frenchman named Thierry de Menouville, formed the project of taking this precious insect away from the Spaniards, and of bestowing it upon the French colonies. He landed in Mexico, and concealed so well the object of his voyage, that he managed to embark and carry to St. Domingo several cases containing plants covered with living cochineals. Unfortunately, a revolution which had broken out at St. Domingo prevented him from succeeding in his praiseworthy endeavours. The cochineals died, and the Spaniards preserved their monopoly in the rearing of this insect. In 1806 M. Souceylier, a surgeon in the French navy, succeeded in bringing from Mexico into Europe some live cochineals. He gave them to the professor of botany at Toulon; but this attempt to preserve them was unsuccessful. In 1827 the naturalisation of the cochineal was attempted in Corsica, but without success. During the same year the cochineal was introduced into the Canary Islands, but the inhabitants did not understand the importance of the experiment. They counted the cochineal among the number of noxious insects, and tried in all ways to rid themselves of it. It was only after results obtained by some more intelligent farmers, that the inhabitants of the Canary Islands perceived the profits they might derive. From that time its cultivation was extended, and after the year 1831 it increased rapidly. Thus, the cochineal imported from the Canary Isles in that year amounted to only 4 kilogrammes. In 1832 the amount was 60 kilogrammes, in 1833 it was 660 kilogrammes, in 1838, 9,000 kilo- grammes, and in 1850, 400,000 kilogrammes. The French colonists in Algeria also tried to raise it. In 1831, M. Limonnet, a chemist of 134 THE INSECT WORLD. Algiers, collected some cochineals, and had the merit of first intro- ducing the insect into the colony. On account of bad weather Fig- 93. Branch of the Cactus, with Cochineal Insects on. these first essays were fruitless, but it was not long before they were repeated. HEMIPTERA. 135 M. Loze, surgeon in the navy, undertook to introduce the insect again, and, with M. Hardy, director of the central garden of Algiers, gave himself up, with great intelligence, to the naturalisation and rearing of the cochineal in Algeria. In 1847 the French Minister of War, for the purpose of having the value of the Algerian cochineal fixed by commerce, caused to be sold publicly on the market-place of Marseilles a case of cochineal, the produce of the harvests of 1845 and 1846, from the experimental garden of Algiers, and which contained 17 kilogrammes of this com- modity. Since that time the cultivation of this insect, the beginning of which was due to M. Limonnet, has rapidly developed. In 1853, in the province of Algiers alone, there were fourteen nopaleries, or cactus gardens, containing 61,500 plants. The Government at that time bought the harvests for fifteen francs the kilogramme. We have only pointed out in a general way how the cochineal harvest is conducted. We will now enter into some details on the subject. These insects are gathered when the females are about to lay, that is, when a few young are hatched. It is when the females are pregnant that they contain the greatest amount of colouring matter. When the harvest time has arrived, the rearers stretch out on the ground pieces of linen at the foot of the plants, and v detach the cochineals from them, brushing the plants with a rather hard brush, or scraping them off with the blade of a blunt knife. If the season is favourable, the operation may be repeated three times in the course of a year in the same 'plantation. The insects thus collected are killed, by dipping into boiling water, by being put into an oven, or by being placed on a plate of hot iron. The cochineals, when withdrawn from the boiling water, are placed upon drainers, first in the sun, then in the shade, then in an airy place. During their immersion in water they lose the white powder which covers them. In this state they are called in Mexico ronagridas. Those which have passed through the oven they call jaspeadas, and are of an ashy grey ; those that are torrefied are black, and are called negras. In commerce three sorts of cochineal are recognised ; first, the mastique (mestique), of a reddish colour, with a more or less abundant glaucous powder ; secondly, the noire, which is large and of a blackish brown ; thirdly, the sylvestre, which is, on the contrary, smaller and reddish. The latter is the least esteemed, and is gathered on wild cacti. Each year there are imported into France 200,000 kilogrammes of cochineals, which represents a value of about three millions of francs. Every one knows that it is from cochineal that carmine is I$6 THE INSECT WORLD. made, a magnificent red frequently employed by painters. Lake carmine is another product obtained from the cochineal. And, lastly, scarlet is the powder of the cochineal precipitated by a salt of tin. Before the Mexican cochineal was known in Europe, the kermes, or Coccus ilicis, known still in commerce and by chemists under the names of Animal kermes, Vegetable kermes, and Scarlet seed, was used for the preparation of the carmine employed in the arts. This cochineal lives by preference (at least, so it is supposed) on the ever- green oak ( Quercus ilex), whence its specific name. The Coccus ilicis develops itself almost exclusively, not on the evergreen oak, but on the Quercus coccifera, or kermes oak, a shrub common in dry arid places on the Continent, and which vegetates on a great number of spots in the Mediterranean, particularly on the garrigues, or waste land, of Herault. The females of this insect, which, dried, bear the name of graines de kermes, are of the size of an ordinary currant, without any trace of rings, nearly spherical, of a violet and glaucous colour. They adhere to the boughs of the shrub Quercus coccifera, and form dry brittle masses, which the peasants of the south of France collect, and sell at a tolerably high price. Before we possessed the cochineal of Mexico and of Algeria, this cochineal was very much employed in the south of Europe, in the East, and in Africa. It furnishes a beautiful red colour. This last named and the Mexican cochineal are somewhat used in pharmacy. They enter into alkermes, a sort of liquor served at dinner in Italy, chiefly at Florence and Naples. Another species of cochineal is the Coccus polonicus, which is met with in Poland and Russia, more rarely in France, on the roots of a small plant, the Scleranthus perennis. This cochineal is gathered in the Ukraine towards the end of June, when the abdomen of the female is swollen, and filled with a purple and sanguineous juice. The Polish kermes ( Coccus polonicus} was formerly used very much in Europe. This product has not indeed lost all its importance in those countries where it is met with in abundance. We have now only to point out among the insects of this group the Coccus lacca, which lives in India on many trees, among others on the Indian fig-tree, the Pagoda fig-tree, the Jujube tree, on the Croton, &c. These last-mentioned insects produce a colouring matter known under the name of Lac Dye. They fix themselves on the little branches, getting together in great numbers, forming nearly straight HEMIPTERA. 137 lines. The bodies of many fecundated females, united together by a resinous exudation which is caused by the piercing of the bark, constitutes the matter called in commerce and by dyers by the name of Lac Dye, Shell-lac, Gum-lac, &c. Resinous lac is found in commerce under four forms : First, the stick-lac, such as it is found concreted at the extremity of the branches whence it exudes it is an irregular brownish crust; secondly, the seed-lac, picked off the branches and pounded ; thirdly, shell-lac in scales melted down and run into thin plates, which vary in quality according to the proportion of colouring matter they contain ; fourthly, thread-lac, which resembles reddish threads, and is prepared thus in India. One more word about the cochineal. The Coccus manniparus, which lives on the shrubs (Tamarix mannifera) on Mount Sinai, causes to exude from the branches it has pierced a sort of manna. The Coccus sinensis produces a kind of wax which is employed, in China in the manufacture of candles. 133 IV. LEPIDOPTERA. THIS order of insects is known popularly by the names of Butterfly and Moth. Linnaeus gave them the name of Lepidoptera^ meaning insects with scaly wings (xeirfj, a scale ; and irreptv, a wing). They are to be found in great numbers in all parts of the world. All the insects contained in the order are, in their perfect state, remarkable for the elegance of their shape, the rapidity and airiness of their flight, and the multiplicity and beauty of their colours. Before they arrive at this perfect state, the Lepidoptera have to undergo three complete transformations. They leave the egg in the larva or caterpillar state ; they pass next to the state of pupa, or chrysalis; they then assume, after a variable time, their final or perfect form. We will study them in their three different states in succession. THE LARVA, OR CATERPILLAR. When the winter has stripped the leaves off the trees, the Lepidoptera are seen no more ; but as soon as the leaves begin to show themselves on the trees and shrubs, this tribe of the insect race again makes its appearance. Caterpillars of all kinds are gnawing at the leaves, even before they are fully developed. Many of them have just emerged from the eggs which the perfect insects had laid at an earlier period ; others have passed the winter in this state. When they come out of the egg the young caterpillars are in shape more or less elongated and cylindrical. Their body is composed of twelve segments, or rings. In front is the head ; then come three segments, on which are the front legs, and which constitute the thorax ; the other segments constitute the abdomen. The head is formed of two scaly parts. It is often very deeply hollowed out on its upper side, and divided into two lobes, which contain in the angle formed by their separation the different parts of the mouth. The head is uniform, rarely having, so far as our cater- LEP1DOPTERA. 139 pillars are concerned, any protuberance ; but in the tropical species it is often armed with prickles, spikes, and extraordinary appendages. They are provided with six small simple eyes, isolated from each other. The mouth is armed laterally with a pair of very solid horny mandibles, articulated by means of vigorous muscles, and moving horizontally. It is the function of the mandibles, as with the jaws, to divide the creature's food. On the middle of a broad under-lip one may perceive a little elongated tubular organ, pierced with a micro- scopic orifice. This organ is the spinning apparatus, which the animal uses in fabricating the threads which it will one day require. It is a tube composed of longitudinal fibres. It presents only one orifice, cut obliquely, and capable of applying itself exactly to the body on which the larva is placed. From the contractile nature of Fig. 94. Scaly legs of the Caterpillar of the Gipsy Moth (Liparis disfar). this organ and the form of its orifice, combined with the faculty the insect possesses of moving it in all directions, result the great differences we observe in the diameter and form of the threads. The external organs of the trunk and abdomen are the legs, the spiracles, and various occasional appendages. The legs are of two different kinds. The one, to the number of six, attached by pairs to the trunk, are covered with a shiny cartilage, and armed with hooks. These are the true legs. Fig. 94 represents, after Reaumur's "Memoire sur les Differentes Parties des Chenilles,"* the scaly legs of the caterpillar of the Gipsy Moth. The others are membranous, fleshy, generally conical or cylindrical, contractile, and taking, according to the will of the animal, very different forms. Fig. 95 represents, after the same Memoir of Reaumur's, the different forms of the membranous legs of the silkworm caterpillar. This plate gives a sufficiently good * Tome i., p. 164 j Plate III., Figs, i, 2. 140 THE INSECT WORLD. idea of the shape of these organs, and of the hooks, circular or semi- circular, with which they are furnished. In Fig. 96 are represented, after the same author, two mem- Fig. 95. Membranous legs of the Silkworm (Bombyx mart). branous legs of a large caterpillar, of which the hooks of the feet are fastened into a branch of a shrub. Caterpillars have from two to ten false legs, the scaly legs being always six in number. The pro-legs, as the fleshy ones are called, are divided into hinder and intermediate. The former are two in number ; the intermediate are rarely more than eight in number. In the caterpillars which have the full number of legs that is to say, sixteen there are two empty spaces, where the body has no support : the one between the legs and the pro- legs, formed by the fourth and fifth segment ; the other, between the intermediate pro-legs and the anal legs, formed by the tenth and eleventh ring. The variations which caterpillars present, so far as the number and situations of their pro-legs are con- cerned, are the following ; The greatest number among them have ten pro-legs ; others have only eight ; others only six these may be called semi-loopers ; others Fig. 06. Membranous legs of a large Caterpillar embracing a twig. LEP1DOPTERA. 141 only four, one pair being situated on the last ring, and the other on the ninth, as in the case of looper caterpillars. And, lastly, there are others which have only two pro-legs. The various forms, numbers, and positions of these organs, produce great differences in the mode of locomotion of caterpillars. Those provided with ten or eight membranous legs have in walking only a very slight undulating motion. Their bodies are parallel to the plane which supports them. They can walk very quickly; but their steps are short and quickly repeated. Others, on the contrary, in proportion as the number of their false legs diminish, and the spaces between the legs increase, walk in a more irregular and quaint manner. If the reader will glance at Fig. 97, taken from Reaumur's " Me'moire sur les Chenilles en general,"* which represents a looper caterpillar, with four membranous legs, he will see that there is a considerable space between the posterior legs and the first pair of pro- legs, along which the body has F 'g- 97- Looper Caterpillar. no points of support. If one of these caterpillars, lying quiet and at full length, determines to walk, in order to take its first step (Fig. 98) it begins by humping its back, curving into an arch that part which has no legs, and finishes by assuming the position seen in Fig. 99. In the former position it has Fig. 98. Caterpillar curved into an arch. Fig. 99. Caterpillar at full length. its two intermediate legs against the posterior legs, and, in con- sequence, it has brought forward the hinder part of its body, a distance equal to the interval of the five segments which separate them. There it hooks on by its intermediate and hind legs. Then it has only to raise and straighten the five rings which had formed the loop, and to advance its head to a distance equal to the length of five * Tome i., p. 49, Plate I., Fig. 6. 142 THE INSECT WORLD. segments. The step is thus made, the caterpillar making the same movements in taking the second and following steps. This sort of gait has gained for them the name of Geometers, because they seem to measure the road over which they travel. When they make a step, they apply the part of their body which they have just curved up to the ground, in exactly the same way as a land surveyor applies his chain to it. These looper caterpillars cannot shorten nor lengthen their seg- ments at will, as other caterpillars, but only bend their bodies. Fig. loo. Caterpillar of the Canary-shouldered Thorn (Evgotiia alniaria). There are many species whose bodies are cylindrical, stiff, and of the same colour as bark. Their attitudes deceive even the close observer. They embrace the stem of a leaf or twig with their hinder and intermediate legs, whilst the rest of their body, vertically elevated, remains stiff and immovable for hours together. Fig. 100 shows the caterpillar of the Canary-shouldered Thorn (Eugenia alniaria} in this strange position. Now, this is a feat of strength which the most skilful of our acrobats, ordinary and extraordinary, which all the Leotards of the present day, and those who are to succeed-them, can never accomplish. With such a persistency, this caterpillar can LEPIDOPTERA 143 sustain its body in the air for a considerable time, in all the positions imaginable, between the vertical and the horizontal, and downwards again in any incline from the horizontal to the vertical. " If one considers," says Re'aumur, "how far we are from having in the muscles of our arms a force capable of supporting us in such attitudes as these, we must own that the power of the muscles in these insects is prodigious." We will not dwell now on the variableness of the length of the body of caterpillars ; on the fleshy appendages which are to be observed on them ; on the hairs which either beautify or render them hideous, according to the fancy of the observer; nor on the various colours with which they are decorated. We will notice these various characteristics when giving the history of some species of remarkable Lepidoptera. Many caterpillars are solitary ; others live in companies more or less numerous, either when young, or during the whole of their existence. With the exception of a great number of moths, which live at the expense of our furs, or woollen stuffs, and leather or fatty matters, all caterpillars feed on plants. From the root to the seeds, no part of the vegetable is safe from their attacks. The greatest number of the species, however, prefer the leaves. Those of the most acrid and poisonous are no more spared than those of the most harmless plants. There are caterpillars which eat the leaves of the Euphorbia, or spurge, for instance. " I wished to try," says Re'aumur, "the milk of this plant on my tongue. It produced hardly any effect upon it at first ; but after a quarter of an hour I found my mouth on fire, and it was a heat which reiterated garglings with water during many hours in succession could not quench. This continued till the next day. The heat passed successively from one part of my mouth to another. I, however, saw many of my caterpillars drinking greedily the great drops of milk which were at tht end of the broken stem I had presented to them." Is it not extraordinary that there are caterpillars which live on the nettle ? that they eat the leaves of this plant, armed as it is with stinging bristles, which cause such smarting and itching to the skin, and produce blisters upon it. It has often been said that each plant has its own peculiar species of caterpillar. All we can say is, that a certain number of vegetables only suit certain caterpillars. The species which eat roots are few ; those which live in the interior of stalks or stems which they feed on 144 THE INSECT WORLD. are numerous, and those which nourish themselves on the pulp of fruits are rare. In general, after the leaves, the caterpillars prefer the flowers : in this they certainly do not show bad taste. Their growth is more or less rapid, according to the species, according to the nourishment they take, and according to the season of the year. Those whose food is succulent grow more rapidly than those which have for their food dry gramineous plants and coriaceous lichens. Most of them eat at night, and remain during the day motionless, and as it were in a state of torpor ; others are so voracious that they are constantly eating. This voracity is indeed sometimes surprising. Malpighi has observed that a silkworm often eats in a day mulberry leaves equal to its own weight. How could we provide our horses and oxen with provender, if they required each day their own weight of hay and grass ? There are even some caterpillars which are still more voracious than that. Re'aumur weighed several caterpillars of a species which lives on the cabbage, and gave them bits of cabbage- leaves which weighed twice as much as their bodies. In less than twenty-four hours they had entirely consumed them. In this space of time their weight increased one-tenth. Fancy a man whose weight is 180 Ibs. eating in one day 360 Ibs. of meat, and gaining 1 8 Ibs. in weight ! Caterpillars eat by the aid of two jaws or mandibles so broad and solid that, considering the smallness of the insect, they are equi- valent to all the teeth with which large animals are fur- nished. It is by the alternate movement of these mandibles that the caterpillars devour the leaves with so much greedi- ness and ease. " A caterpillar, when it wants to gnaw the edge of a leaf," says Reaumur, "twists Fig. 101. Looper Caterpillar eating the /eaves of the v. j T- i Apricot (after Reaumur). its body in such a way that at least one portion of the edge of this leaf is passed between its legs. These legs hold fast that portion of the leaf which is to be cut by the insect's jaws (Fig. 101). To give the first bite the caterpillar elongates its body, and carries its head as far forward as possible. The portion of the leaf which is between the open jaws is cut through the instant the teeth LEP/DOPTERA. 145 meet each other ; the bites succeed each other quickly ; there is not one, or scarcely one of them, that does not detach a bit, and each bit is swallowed almost as soon as cut off. At each fresh bite the head approaches the legs in such a way that during the succession of bites it describes an arc ; it hollows out the portion of the leaf in a segment of a circle, and it is always in this order that it gnaws it." But there is a phenomenon in the life of caterpillars which we ought to point out, and which has attracted the attention of the most illustrious observers. All caterpillars change their skins many times during their life. It is not, indeed, enough to say that they change their skins ; the skins or cases they cast are so complete that they might be taken for entire caterpillars. The hairs, the case of the legs, the claws with which the legs are provided, the hard and solid parts which cover the head, the jaws all these are found in the skin which the insect abandons. What an operation for the poor little animal ! This labour is so enormous, so troublesome, that one cannot form a just idea of it. One or two days before this grand crisis, the caterpillar leaves off eating, loses its usual activity, and be- comes motionless and languid. Their colour fades, their skin dries little by little, they bow their backs, swell out their segments. At last this dried-up skin splits below the back, on the second or third ring, and lets us have a glimpse of a small portion of the new skin, easily to be recognised by the freshness and brightness of its colours. " When once the split has been begun," says Reaumur, " it is easy for the insect to extend it ; it continues to swell out that part of its body which is opposite the slit. Very soon this part raises itself above the sides of the split ; it does the work of a wedge, which elongates it; thus the split soon extends from the end or the com- mencement of the first ring as far as the other side of the end of the fourth. The upper portion of the body which corresponds to these four rings is then laid bare, and the caterpillar has an opening suf- ficiently large to serve it as an egress through which it can entirely leave its old skin. It curves its fore part, and draws it backwards ; by this movement it disengages its head from under its old envelope, and brings it up to the beginning of the slit ; at once it raises it, and puts it out through this slit. The moment afterwards it stretches out its fore part and lowers its head. There now remains for the caterpillar nothing but to draw its hinder part from the old case." This excessively laborious operation is finished in less than a minute. The new livery which the caterpillar has just put on is fresh and bright in colour. But the animal is exhausted by its fast, and the efforts which it has made. It requires a few hours in which to K 146 THE INSECT WORLD, regain its equilibrium, and at the same time its former activity and voracity. THE CHRYSALIS, OR PUPA. Having attained its full development, the caterpillar ceases to eat, as at the approach of a moult, it empties its intestinal canal by copious ejections ; it loses its colours, and becomes dull and livid, and thus prepares itself to enter a new phase of its existence. Some, when about to transform themselves into chrysalides, suspend themselves to foreign bodies. Others spin a cocoon, composed of silk and other substances, which secures them against the attacks of their enemies and the action of the atmosphere. Those which suspend themselves can be divided under two heads, according to the mode of their suspension : i. Those which suspend themselves perpendicularly by the tail. 2. Those which, after having fixed themselves by the same part, suspend themselves horizontally, by means of a silk thread passed round the body. To understand the difficulty which the first of these operations presents, we must consider the problem which the caterpillar has to solve. In this problem there are two unknown quantities to be dis- covered. Firstly, the caterpillar must suspend itself firmly ; and secondly, the pupa, having no communication with the object which supports it, must be suspended in the same manner. This problem is difficult, apparently impossible, to solve. It is only by watching these insects at work that one can discover the wonderful mysteries of their lives. Swammerdam, Valisnieri, and other observers who have studied insects, had not, however, observed the manoeuvres of caterpillars in this curious phase of their existence. It is to Reaumur again that science is indebted for the most charming and valuable observations on this point. He got together a great number of caterpillars of the small Tortoise-shell Butterfly ( Vanessa urticce), black prickly caterpillars which are common on the stinging- nettle, where they live in companies, and suspend themselves by the tail. When the time approaches at which the caterpillars of this species ought to undergo their transformations, they usually leave the plant which had up to that time served them as food. After having wandered about a little, they select some convenient spot, where they hang themselves up head downwards (Figs. 102, 103). In order to hang itself in this way, the caterpillar begins by cover- ing, with threads drawn in different directions, a pretty large extent of the surface of the body against which it wishes to fix itself. After having covered it thus with a kind of thin cobweb, it adds different LEPIDOPTERA. 147 fy (Vanessa urticix) undergoing their metamorphoses. layers of threads on a small portion of this surface, in such a manner that the upper one is always smaller than that upon which it is laid. In this manner a small hillock of silk is formed, the tissue of which is not at all compact. It resembles an assemblage of loose or badly interwoven threads. The membranous feet of the caterpillar are armed with hooks of different lengths, with the aid of which it sus- pends itself. By alternately contracting and elongating its body, it pushes its hindermost legs against the hillock of silk, presses against it the hooks of its feet, so as to get them better entangled, and lets its body Figs. 102, 103. Caterpillars of the small Tortoise-shell fall in a vertical position. It remains hanging thus, often for twenty-four hours, during which time it is oc- cupied in a difficult task, that of splitting its skin. In order to effect this, it incessantly curves and recurves its body (Fig. 102), until at last a split appears on the skin of the back, and through this split emerges a part of the body of the chrysalis. This acts as a wedge, and little by little the split widens from the head to the last of the true legs, and beyond them. Then the open- ing is sufficient to allow of the chrysalis drawing out its anterior portion from the en- velope, which it immediately does. To set itself entirely free, the chrysalis lengthens and shortens itself alternately (Fig. 105). Each time that it shortens itself, and when it consequently distends the part of its body which is outside the old skin, that parts acts against K 2 Figs. 104, 105. -Chrysalides of the small Tortoise- shell Butterfly freeing themselves from the Caterpillar skin. 148 THE INSECT WORLD. the edges of the slit, and gradually pushes the old skin upwards. Thus the caterpillar skin ascends, its plaits are pushed nearer and nearer together, and it is soon reduced to a packet so small that it covers only the end of the tail of the chrysalis (Fig. 106). But here comes the culminating point, the most difficult part of the operation. The chrysalis, which is shorter than the caterpillar, is at some distance from the silky network to which it must fix itself ; it is only supported by that extremity of the caterpillar's skin which had not been split open. It has neither legs nor arms, and yet it must free itself from this remaining part of the skin, and reach the threads to which it is to suspend itself. The supple and contractile segments of the chrysalis serve for the limbs which are wanting to it. Between two of these segments, as Fig. 106. Chrysalis of the small Tortoise- shell Butterfly completing the operation Fig. 107. Chrysalis divested of the larva of casting its larval skin. skin. with a pair of pincers, the insect seizes a portion of the folded skin, and with such a firm hold that it is able to support the whole of its body on it. It now curves its hinder parts slightly, and draws its tail entirely out of the sheath in which it was enclosed. It then reposes for an instant only, for it has not yet finished the laborious operation of its deliverance. It must free itself entirely from the dry skin which surrounds the extremity of its body. The insect curves the part which is below its tail in such a manner that that part can embrace and seize the packet to which it holds on. It then gives to its body a violent shock, which makes it spin round many times on its tail, and that with great rapidity. During all these pirouettes the chrysalis acts against the skin ; the hooks of its legs fray the threads, and break them or disentangle LEPIDOP TERA . 1 49 themselves from them. Sometimes the threads do not break at once. Then the animal recommences its revolutions in an opposite direction, and this time it is almost certain to succeed. Reaumur, however, saw a chrysalis which, after having tired itself in vain in its endeavours to get entirely free of its old skin, despairing of ever being able to manage it, abandoned it where it was so solidly fixed. We represent (Fig. 107), rather magnified, the chrysalis arrived at its final state, and suspended to a branch of a tree by a network of silk.* We come now to the mode of suspension employed by those caterpillars, which, after having fixed themselves by the tail, strengthen the support by means of a small silk cord passed round their body. It is again to Reaumur, that indefatigable observer of the habits of insects, that we go for the details of this manner of suspension. According to Reaumur, these caterpillars make and put on this belt in three different ways. But of these three ways the simplest, and the least liable to meet with accident, is that employed by the larva of the Cabbage Butterfly (Pieris brassicce). When the time for its metamorphosis is only a few days distant, one may observe this caterpillar engaged in stretching threads on different parts of the case in which it is confined. It then chooses a spot, which it covers entirely with threads, some more compact than the others, and disposed in layers, which cross each other in different directions. These threads form a thin white cloth, against which the belly of the caterpillar and later that of the chrysalis are applied. Very soon we see a small hillock of silk rising. The caterpillar hooks itself on to this by the claws of its hinder feet, and sets to work to secure itself. To understand this process, it suffices to know that after having lengthened its body to a certain point, this caterpillar can turn back its head on to its back, and reach to the fifth ring, having its three pairs of true legs in the air. But without putting the caterpillar into such an unnatural position, let us take it in a position in which it is simply bent sideways in such a manner that its head, with the thread- spinning apparatus, which is below, can be applied opposite and pretty near to one of the legs belonging to the first pair of mem- branous legs. Our caterpillar begins by fixing on this point a thread, which is the first of those that are intended to tie it up securely. " This thread," says the illustrious author of the " Memoires pour servir a 1'Histoire des Insectes," must pass over the caterpillar's body ? * It has been remarked that only those whose continuance in the pupal state is short, undergo their metamorphosis in this apparently inconvenient position. ED. ISO THE INSECT WORLD. and be attached by its other end near the leg corresponding to that near which the first end was fastened. To spin the thread the proper length, and at the same time to fix it in its proper place, the cater- pillar has only to bring round its head to the fifth segment. The thread will be drawn from the spinning apparatus as the head advances over half the circumference of the circle which it has to describe ; and when it has described this, there will only 08. Caterpillars of the Cabbage Butterfly (Pier is brassicai). remain for it to secure the second end of the thread against the support. Thus the head, which was at first placed against one of the legs, advances little by little on the outline of the fifth ring as far as to its middle (Fig. 108). It is the facility the caterpillar has of reversing its body that enables it to make its head perform this journey, in proportion as it moves it over the circumference of the ring, it twists its body. And at last, when it has brought it over the top of the segment, its body is exactly folded in two ; it draws it little by little from this situation by bending towards the other side, and by causing its head to pass gently over the last quarter of the circle. At last the caterpillar finds itself bound on the second side ; the head rests on the thread-covered plane, and the insect fixes the second end of the thread." It has only to repeat the same manoeuvre as many times as there LEPIDOPTERA. Fig. 109. Caterpillar of the Pieris brassicae. are threads wanted to make a strong band. But each thread embraces the head, or rather the lower part of the head, for it knows how to make each thread it spins glide into the bend or crease of its neck by a little move- ment of its head. It must disengage its head from under the band, not a difficult operation. It causes it to slide along the threads near one of the places where they are fixed, and it is then in the position indicated by the foregoing engraving (Fig. 109). About thirty hours after the caterpillars have succeeded in making themselves fast, they have completed their transformation into chrysalides (Fig. no), where the chrysalis of the above- mentioned caterpillar is seen in two different posi- tions, and held by the same band which first supported the caterpillar. Those caterpillars which construct cocoons make them of silk and other substances. These cocoons are, for the most part, oval or elliptical, sometimes boat-shaped, and ordinarily white, yellow, or brown in colour. The threads may very slightly adhere together, or be closely united by a gummy substance with which the caterpillar lines the interior of the cocoon, and which it expels from the anus. Some cocoons are com- posed of a double envelope, others are of a uniform texture. Some are of a tissue so close that they entirely hide the chrysalis contained within ; others form a very light covering, through which the chrysalis can be easily perceived (Fig. in). Among caterpillars that make a very slight cocoon, some, as the Catocalas, gather together two or three leaves into a ball, to protect them. Others strengthen their cocoons, and render them p up3 . O f Herfs opaque by adding earth or other substances, often obtained from their own bodies. Some, after having spun their cocoon, cast forth through the anus three or four masses of a matter 152 THE INSECT WORLD. resembling paste, which they apply with their head to the inside of the cocoon, and which, drying quickly, becomes pulverulent. Others employ for the same purpose the hairs with which their bodies are covered. The larva of Acronycta aceris (Fig. 113) is covered with tufts of yellow hair. Reaumur made these caterpillars work under his own eye in glass vases. They make the layer which is to form the exterior surface of their shell, or cocoon, of pure silk, and when it is thick enough, tear out their hair, now from one place, now from another. But we will leave the illustrious observer to relate this operation himself, which must without doubt be painful to the poor animal : " Its two jaws are the pincers the caterpillar uses in seizing a portion of one or other of the tufts of hair ; and when it has seized it, it tears it out without much Cocoon, T ig. in. after Re Fig. 113. Larva of Acronycta aceris. difficulty. It at once places this against the tissue it has already commenced, in which it entangles it at first simply by pressure ; it LEP1DOPTERA. 153 fixes it then more securely by spinning over it. It does not leave off tearing out its hairs till it has entirely stripped them off. When the caterpillar has taken between its jaws and torn out a whole tuft of hair, the head carries it and deposits it on some part of the lower surface of the cocoon ; but it does not leave the hairs of such a large parcel together. The next moment one sees its head moving about very quickly ; then taking a portion of the hairs from the little heap, it distributes them about on the neighbouring parts of the cocoon. If one opens one of these shells before the cater- pillar has become a chrysalis, the larva, which is quite naked, and which was only known by its hair, can be no longer recognised." The caterpillar of the Tiger Moth, or Woolly Bear, called by Reaumur Marie or Herisson (Chelonia caja, Fig. 116), is covered with long inclined hairs. This caterpillar also makes use of its hairs for strengthening the tissue of its cocoon ; but whether it feels the pain more acutely than the former, or whether it would Fig. 114. Larva of Acronycta aceris 15. Larva of Acronycta aceris taker of its cocoon. a of Chelonia caja. suffer more, it does not tear out its hairs. It adopts another system ; it cuts them. The caterpillar is then enveloped on all sides in its hair, which is to serve in the construction of its cocoon. 154 THE INSECT WORLD. Another species uses its hairs in the composition of its cocoon ; but it adopts an entirely peculiar way of tearing them out, when the tissue of its cocoon has become a species of network of pretty closely packed rings. Rdaumur one day saw one part of the cocoon bristling with hairs. These were the hairs of a part of the back of the caterpillar, which it had pushed through the rings of its cocoon. The caterpillar then moved about as if rubbing this part of its back successively in opposite directions against the interior surface of the cocoon. In this way the hairs were very soon torn out and kept retained in the rings of the cocoon. This cocoon is then bristly inside, and does not at all suit the future chrysalis, which does not like to be touched by any but smooth sur- faces. The caterpillar then works with its head, to lay the hairs along the interior surface, and to keep them down by threads, which it draws over them. At another time Reaumur saw a small hairy caterpillar, which appeared to live on lichens, using its hair in another way. It tore them out to make its cocoon, but it was not to lay them down and work them into a tissue. It set them straight up Larva of Chelonia caja forming its cocoon. 8. Small Caterpillar of the Pimpernel. Fig. 119. Cocoon of the same. like the stakes of palisades, on the circumference of an oval space, in which it was placed. Shut up within this palisade, it spun a light white web. This web supports the hairs, causing the greater part of LEPIDOPTERA . 155 them to curve at their upper extremity, in such a manner as to form a sort of cradle. It remains for us now to speak of the caterpillars that make their cocoons of silk, together with other materials. Reaumur saw the Pimpernel caterpillar arranging and sticking together the leaves of that plant, and spinning underneath them a thin cocoon of white silk (Fig. 119). Some caterpillars make their cocoons on the surface of the earth, Fig. 120. Larva of Cucullia verbasci. and even with earth. These cocoons are spherical or oblong. Their exterior is more or less well shaped, but their interior is always smooth, polished, shining like moistened earth, worked up together into a kind of paste, and carefully smoothed out. This cocoon is besides lined with a covering of silk of vari- able thickness. The shell is not made of earth alone ; threads of silk may be seen in it, crossing each other, and binding together the particles of earth. These subterranean workers do not allow their proceedings to be Fig . I2I ._ C ocoon of the Cu easily observed. Reaumur was for- tunate enough to be able to notice their skill in the construction of their shells or cocoons. The Cucullia verbasci (Fig. 120) makes itself a thick and very compact cocoon of the form of an egg (Fig. 121). Reaumur took one of these out of the ground before it is fortified. He tore it partially open, and placed it in a glass vase containing sand, but the poor insect was not long in repairing the disorder caused by the rough hand of our naturalist. It only took four hours to restore its cocoon to its former state. " It began," says Reaumur, " by coming almost entirely out, and 156 THE INSECT WORLD. left only its hinder part within. It moved its head forwards as far as was necessary to enable it to seize a particle of earth. As soon as it had got its load, it re-entered the interior of the cocoon. It deposited the grain of earth, and came out again immediately, as it did at first, to pick up another grain, which it carried likewise into the interior of the cocoon. This operation it continued for more than an hour. . The provision of materials being got together, the caterpillar now devoted his whole attention to working them up. It began by spinning over one part of the edges of the opening. After having put over this a small band of very loose web, the caterpillar's head left the opening, the insect went right back again into its cocoon, and the head returned to the opening loaded with a little grain of earth, which it entangled in the silky threads. It then entangled in them two or three, or a greater number of grains, according to the quantity of threads it had spun. It bound them into these with other threads, after which it drew threads over the edges of another part. By thus going round the whole rim of the opening, and by carrying and fixing the grains of earth in the threads which were the last stretched over the opening, it rendered its diameter smaller and smaller." It was by working with its head that our mason gave to the new wall of its cocoon the necessary curvature. It was interesting to know how, as it could no longer put out its head, it could stop up the orifice. "It knew how to change its manoeuvres. When the opening was reduced to a circle of only a few lines in diameter, it drew threads from a point on the circumference to another on the other side. Thus the opening was covered in with a rather open net-work As soon as this web was finished, it got a grain of earth (which it had laid by until it was wanted), brought it up, placed it against the web, and by pushing and pressing it, made it pass through the web until it reached the exterior, and so in succes- sion the whole of the web was covered with grains of earth It was not satisfied with rendering the exterior of this place exactly like the rest of the shell ; it fortified it thoroughly ; it added to it, one after another, layers of grains of earth, till it was as solid and as thick as the rest." The larva of Pyralis corticalis, which is found on oak trees in the month of May, shows to what a point these little insects carry their industry in the construction of their cocoons, in the choice of their materials, in their manner of working them up, and in the forms they cause them to assume. Reaumur one day saw this caterpillar on a small branch, between two triangular appendages (Figs. 122, 123). LEPIDOPTERA. 157 This was the beginning of a cocoon. Each triangular blade was composed of a great number of small, thin, rectangular plates, taken Figs. 123. Cocoon of Pyralis corticalis (magnified, proper size | inch). from the bark of the twig. The caterpillar detached with its jaws a small band of bark, and fitted it on, and adjusted it with admirable precision against the edge already formed. It then fixed it securely 158 THE INSECT WORLD. with silk threads. Reaumur saw this caterpillar work and erect in this way a large blade during an hour and a half. "When one sees," he says,* "an insect which, to construct a cocoon, begins by collecting together an infinite number of small plates of bark in order to compose of them two flat triangular blades ; which, to gain its end, takes means that seem so roundabout, although they are the most suitable and the quickest it could adopt, one is very much tempted to consider such an insect, when one sees it thus acting, possessed of reason." These two blades are at last transformed into a regular cocoon. The little animal, which is at the same time architect, cabinet-maker, and weaver, arranges it in such a way as to form a hollow cone, which it only remains for it to shut. Reaumur calls this sort of cocoon or shell, la cogue en bateau, the boat-shaped cocoon. Some caterpillars weave cocoons of the same form with pure silk. To bring this subject to an end, we will mention the industry of the Puss Moth (Dicramira vinula), and that of a small Tinea, which eats the barley stored away in our granaries. The larva of the puss moth employs in the construction of its shell the wood of the tree on which it has lived. It bites it up, and mixing it with a glutinous fluid which it secretes from its mouth, reduces it to a sort of paste, which it then uses in the formation of an envelope, of such hardness that a knife can hardly cut into it. The Tinea lines the interior of a grain, of which it has previously devoured the contents, with a coating of silk, and divides it thus into two different chambers. In one of these it is to change into a pupa ; in the other it places its excrement. And so the little careful architect constructs its house in such a manner as to find in it tranquillity, cleanliness, and comfort. When caterpillars have not within their reach the materials they are in the habit of employing, like good workmen, they content them- selves with what they can get. Re'aumur reared a caterpillar which formed its cocoon of pieces of the paper of which the box was made in which it was imprisoned. What an extraordinary condition ! what a strange phase of vitality does the chrysalis present to us a being occupying the middle state between the caterpillar and the perfect insect ! How little does it resemble that which it previously was, and what it will become ! In appearance it is scarcely a living being ; it takes no nourishment, and has no digestive organs ; can neither walk nor drag itself along, and * Mem. 12, vol. i., p. 487. LEPIDOPTERA. 1 59 hardly bends the joints of its body. The outside skin of the chrysalis appears to be cartilaginous ; it is generally smooth, although some species have hairs scattered over their bodies. We distinguish in chrysalides two opposite sides. The one is the insect's back, the other its under side. On the upper part of the latter (Fig. 124) we perceive various raised portions, formed and arranged like the bands round the heads of mummies ; the back is plain and rounded in a great number of pupse ; but a great many others have on the upper part, along the edges which separate the two Fig. 124. Fig. 125. Fig 126. A conical pupa. Pupa having angular projections. Angular pupa of a Butterfly sides, little humps, eminences broader than they are thick, ending in a sharp point (Fig. 125). The head of the angular pupse terminates sometimes in two angular parts, which diverge from each other like two horns (Fig. 126). In some other cases they are curved into the form of a crescent. These appendages sometimes give to the pupa the appear- ance of a mask, especially as an eminence placed on the middle of the back is rather like a nose, and the small cavities may represent the eyes (Fig. 125). The colours of angular pupae attract our attention. Some are superbly tinted ; they appear to be wrapped in silk and gold. Others have only spots of gold and silver on their belly or their back. All, however, have not this remarkable splendour, not these metallic spots. Some are green, yellow, and spotted with gold. Generally they are brown. Reaumur has shown that this golden colour is not due, as was thought for a long while, to colouring matter, but to a little whitish membrane, placed under the skin, which reflects the light through the thin outer pellicle, in such a manner as to produce the I6O THE INSECT WORLD. optical illusion which imparts to the robe of the chrysalis the golden hues of a princess in grand costume. All is not gold that glitters, Rdaumur proves literally, in the case of chrysalis.* Let us add that the chrysalis remains thus superbly dressed as long as it is tenanted, but loses its colour as soon as the butterfly has quitted it. The cone-shaped pupae belong to the twilight and night-flying Lepidoptera, and to those butterflies whose caterpillars are onisci- form, or in shape resembling a wood-louse. They are generally oval, rounded at the head, and more or less conical at the lower end. Their colour is generally of a uniform chestnut brown. What a mystery is that which is accomplished in the transition from the chrysalis to the perfect state ! Those great changes from the larva state to that of the pupa, and from the pupa to that of the imago, are accomplished with such rapidity, that the phenomena were looked on as sudden metamorphoses, like those related in mythology. It has been thought also that there was in these changes from one state to another a sort of resurrection. There is here neither sudden metamorphosis, nor, as we will show, resurrection. In fact, the chrysalis is a living being ; it indeed shows its vitality by exterior movements. Under the old skin of a caterpillar about to moult, under the envelope which is soon to be cast off, the new integuments are being prepared. Some days before the moult, split the caterpillar's skin, and you will find the skin which is to take its place already beneath. If, some days before the transformation of the caterpillar into a chrysalis, it is dissected, the rudiments of wings and antennas may be dis- covered. If a chrysalis is examined on the outside, all the parts of the future insect can be distinguished under the skin : the wings, the legs, the antennae, the proboscis, &c. ; only, these parts are folded and packed away in such a manner that the chrysalis can make no use of them. It could not, moreover, make use of them on account of their incomplete development. Fig. 127 shows, after Reaumur, t a chrysalis magnified and seen from its lower side, on which we observe : a, the wings ; b b, the antennas ; t, the trunk or proboscis. There is a moment when these parts, pressed one against each other, and as it were swathed up like a mummy, are very easily seen, for they are, as we may say, laid bare. This moment is that in * The word is derived from xP u ' golden ; for that reason pupa is a better word than chrysalis, as this only strictly applies to a very small number ; for the same reason aurelia is a bad word. ED. f Tome i., p. 382, planche 26, Fig. 6. LEPIDOPTERA. 161 which the pupa has just quitted the caterpillar's skin. It is then still soft and tender. Its body is moistened with a liquid, which, drying rapidly, becomes opaque, coloured, and of a membranous consistency. The result is that the parts which did not cohere in the least when the chrysalis made its first appearance, are fastened together, so that al- though they could at first be seen, through a layer of transparent fluid, they are now hidden under a sort of veil or cloak. It is necessary to seize then the moment of the birth of the chrysalis, to observe it accurately. On examining the pupa before the liquid which pervades these parts has had time to dry, it resembles the perfect insect. All the exterior parts which belong to the imago can be dis- tinguished. One recognises the head, which is then resting on the thorax; the two eyes and the antennae (Fig. 128), which are brought for- ward like two ribbons ; the wings also brought over the thorax, but these are separated arti- ficially in the drawing we have given after Reaumur ; * and lastly in the space left between the wings, the six legs, and the body of the insect. To sum up : the pupa, when it approaches the period for being hatched is only a swaddled butterfly. Directly it has strength enough to rid itself of its wrapping, the insect frees itself from its fetters ; it flies away, brilliant and free, and its many-coloured wings glitter in the sun. The duration of the pupa state is variable, according to the species and the temperature. Reaumur placed in a hot-house, in the month of January, some pupae which, in the ordinary course of things, would not have been hatched till the month of May, and a fortnight afterwards the images had appeared. On the other hand, he shut up some pupae in an ice-house during the whole of a summer, and thus retarded their being hatched by a whole year. The influence of the temperature on the period of emerging, and, consequently, the influence of the seasons on the length of this period, are completely brought to light by these experiments.! * Tome i., p. 382, planche 26, Fig. 7. t They hardly seem from later experiments to be so fully explained. It is a L Fig. 127. Chrysalis of the large Tortoise-shell Butterfly (Vanessa polychloroi), magnified, seen from the lower side. 1 62 THE INSECT WORLD. We will now see how the insect delivers itself from the last skin. To quit the pupa case is not so laborious an operation as it was for the same insect to quit the caterpillar's skin. This is because the pupa case is drier ; it does not adhere to every part of the body, and is brittle. Those insects which are enclosed in a cocoon free them- selves of the pupa envelope in the cocoon itself. To witness the last operation, the cocoon may be opened, and the pupa drawn out Fig. 128. Chrysalis of the Large Tortoise-shell Butterfly ( Vanessa polyckloros) whose different parts have been opened before they were fastened down. (a, wings ; bb, antennae ; t, trunk, or proboscis.) of it with care. If it is then placed in a box, the metamorphosis may be observed. To study this last evolution more at his ease, Reaumur covered a large extent of the wall of his study with pupae of the Vanessa polychloros and other species. When the parts of the body of the insect have attained a certain degree of solidity within the envelope, it has no great difficulty in making the thin and friable membrane which surrounds it split in different places. If it even distends itself or moves, a small opening will be made in the dried skin. If the movements persist, the well-known fact that many insects remain in this state a variable time the Small Eggar (Bombyx lanestris) sometimes as many as seven years. ED. LEPIDOP7EKA. 163 Fig. 129. Moth just emerged. opening increases in size, and very soon allows the imago to emerge. It is on the middle of the upper part of the thorax that the envelope begins to split. The split extends over the middle of the forehead and back. The pieces of the thorax open, separate themselves from the other parts to which they were fixed, and the insect can take advantage of the opening which is made, and escape. Little by little also it advances its head. The head is the first out of the old skin, and the insect sets itself entirely free. This occupies rather a long time ; for we must remember that, under the pupal envelope, its legs, its antennae, its wings, and many other parts, are enclosed in special cases. These peculiar circum- stances show that the animal has much trouble and must employ some time in setting free all the parts. At last our prisoner has come out of its narrow cell, and is delivered from its old covering. What poet can describe to us the sensations of this charming and frail creature which has just risen from the tomb, and for the first time is enjoying the splendid light of day, the radiant sky, and the flowers redolent with delicious perfumes, which are inviting it to kiss and caress them ! The wings strike one most. They are very small at the time of birth. Fig. 129 represents, after Reaumur,* a moth at the moment in which it has just emerged from the pupa. But at the end of a short period the wings become developed ; only they are wrinkled, as Fig. 130, given by Reaumur, represents. Re'aumur having taken between his fingers a very short wing of a butterfly which was just hatched, drew it about gently in all directions. He succeeded thus in giving it the whole extent it would have assumed naturally. According to Reaumur the wing of a butterfly just born, which appears so small, is really already provided with all its parts, only it is folded and re-folded on itself. He supposes that what his hands did to lengthen the butterfly's wings, is done naturally Fig. 130. Moth whose wings are folded up. * Tome i., p. 654, planche 46, Fig. I. L 2 IO4 THE INSECT WORLD. by the liquids which are contained in the insect which has just emerged, and whose wings are no longer confined in their cases. At the time of its birth the wings are flat and thick ; as they grow, little by little they spread themselves out and become curled up. When they are completely developed and flattened the wings become firm and hard imperceptibly, and this firmness extends at the same time to the whole of the body. Figs. 131 and 132, borrowed, like the preceding, from the i4th Fig. 131. Moth whose wings are developing. Fig. 132. Moth whose wings are developed. Memoir of Reaumur (sur la transformation des chrysalides en papillons), show the states through which the wings of the same moth pass, before they are thoroughly developed. Those pupae enclosed in cocoons free themselves entirely or in part from their old skin, in the shell itself; but the imago is still a prisoner. It has broken through a first enclosure ; it must open itself a way through the second. How does it manage to bore through the often very solid walls of this second prison, so as to regain its liberty ? Reaumur states that in the Lackey Moth {Bombyx neustria) the head is the only instrument of which the insect makes use in opening a passage, the compound eyes then acting like files. These files cut the very fine threads of which the cocoon is composed, and as soon as the end of the cocoon is pierced through, the insect uses its thorax like a wedge, to enlarge the hole. It very soon manages to get its two front legs out, fixes itself by them on to the outside, and little by little emerges from its prison. LEPIDOPTERA. THE PERFECT INSECT. i6 5 Who does not admire the extraordinary splendour, the vivacity, the prodigious variety of colours of these brilliant inhabitants of the air ? Some amateurs have devoted to the purchase of certain butter- flies large sums of money. " Diamonds," says Reaumur on the subject, " have perhaps beauties no more real than those of a butter- fly's wings ; but they have a beauty which is more acknowledged by the world in general, and which is more recognised in commerce." 33- Different forms of the scales of Butterflies, after Reaumur. The essential character of butterflies and moths makes them very easily recognisable among all other insects. All have four wings, which are covered with scales, that communicate to them the brilliant colours with which they are decorated. It is these scales which adhere to the fingers when we seize one of these charming creatures. For a long time this dust was thought to be formed of very small feathers, but Reaumur showed that it is composed of little scales. Their form varies singularly, as we may see in Fig. 133, borrowed from the Memoirs of Re'aumur,* which represents the different forms of the scales which cover the wings of Lepidoptera. M. Bernard * Tome i., planche 7, Figs. I a 23. 166 THE INSECT WORLD. Deschamps has closely studied them. According to this naturalist, they are composed of three membranes, or plates, superposed one on the other, of which the first is covered with granulations of a rounded form, which give to these scales their splendid and varied colours ; the second plate is covered with silk, forming sometimes curious designs ; the third plate, viz., that which is applied to the membrane of the wing, has the peculiar property of reflecting colours the most brilliant and the most varied, although the surface of the scales visible to the eye is often dull and colourless. " Supposing," says M. Bernard Deschamps, " that a painter was possessed of colours rich enough to represent on can- vas with all their splendour, gold, silver, the opal, the ruby, the sapphire, the eme- rald, and the other precious stones which the East pro- duces, that with these colours he formed all the shades which could result from their combination, one might af- firm without the chance of contradiction, that he would have, none of these colours and of their various shades, Fig. ^--Portion .of^the ng^gjh (Saturnia ^^^ ^^ be ^ num . ber, which could not be discovered by the microscope on part of the scales of the Lepidoptera, which Nature has been pleased to conceal from our gaze." Each of these scales adheres to the membrane of the wing by a small tube, which is solidly fixed to it. Reaumur has called our attention to the admirable arrangement of these scales, which are disposed like those of fish, that is to say, in such a manner that those of a row shall partially overlap those in the following one. In Fig. 134, representing a portion of the wing of the Saturnia pavonia major, magnified, which we borrow from Reaumur's Memoir, the scales are arranged in rows ; isolated scales, and the points where other scales were fixed before they were taken off, are repre- sented. The membranous frame which supports the coloured scales of butterflies and moths is well worth a moment's consideration. It consists of two membranes intimately united by their interior surfaces, LEPIDOPTERA. 1 67 and divided into many distinct parts by horny, fistulous threads, more or less ramified, which seem intended to support the two membranes mentioned above, and which branch out from the base to the edge of the wing. Their number, counting from the exterior edge, is not always the same in the upper and lower wings. It varies from eight to twelve. With its large and light wings, the butterfly can fly for a long time. But this flight is not in the least regular ; it is not made in a straight line. When the insect has to go some distance, it flies alternately up and down. The line it takes is composed of an infinity of zig-zags, going up and down, and from right to left. This irregularity of flight saves the little insect from falling a prey to birds. " I saw one day with pleasure," says Reaumur, " a sparrow which pursued in the air a butterfly for nearly ten minuses without being able to catch it. The flight of the bird was nevertheless considerably more rapid than that of the butterfly, but the butterfly was always higher or lower than the place to which the bird flew, and where it thought it would catch it." But let us leave the wings to pass on to the other parts of the butterfly. These other parts are the thorax or chest, the body or abdomen, and the head. The thorax is solidly put together, so as to bear the movements of the wings and legs. These latter are composed, as in other insects, of five parts : the coxa, the trochanter, the thigh, the shank, and the tarsus. Many butterflies have all their six legs of equal length. In Fig. 135. Leg of Butterfly armed with hooks. Fig. 136. Leg not suitable for walking. others, the two fore legs are very small, and are not suited for walking. In others, again, they are rudimentary, being deprived of hooks, very hairy, and applied on to the front of the breast. This difference of structure may be seen in Figs. 135 and 136, one of which represents, after Reaumur, a leg unsuited for walking, very hairy, and terminated in a sort of brush resembling the tail on a tippet ; and the other a leg furnished with hooks. 1 68 THE INSECT WORLD. The abdomen has the form of an elongated, or in the majority of species an almost cylindrical oval. It is composed of five segments, each formed of an upper and a lower ring, joined together by a membrane. The first are larger than the others, and generally overlap the edges, which gives to this part of the body the power of dilating considerably. We must dwell longer on the head. It is generally rounded, compressed in front, longer than it is broad, and furnished with fine or scaly hairs. The important organs of which this part is the seat are the eyes, the antennae, the palpi, and the proboscis or trunk. The eyes are more or less spherical, surrounded by hairs, and composed of innumerable facettes. Colours are seen on these as various as those of the rainbow. But the colour which serves as a base to all, is black in some, grey in others ; then again there are different gold or bronze colours of the greatest splendour, inclining sometimes to red, sometimes to yellow, sometimes to green. On the compound eye of a butterfly as many as 17,325 facettes have been counted. Simple eyes, or stemmata, are moreover observed in certain species, and are generally more or less hidden by scales. The antennae are situated near the upper rim or border of each eye. Rdaumur has pointed out six principal shapes. One termi- nates in a little knob, and belongs to the butterflies. The others are variously shaped, and belong to the moths. Some are prismatic, or like beading. And lastly, others are shaped like feathers. We re- present, in Fig. 137, the different forms of the antennae, which Re'aumur collected together in plates 8 and 9 of his fifth Memoir.* The palpi are four in number, two maxillary and two labial. The first are generally excessively small ; one can only ascertain their existence by the aid of a strong magnifying glass : the second are in general very apparent, straight, cylindrical, covered with scales, and formed of three joints, of which the last is often very small and some- times very pointed. They also sometimes bristle with stiff or silky hairs. The trunk is placed exactly between the two eyes. As long as the butterfly does not want to take nourishment, the trunk remains rolled in a spiral. Some are so short, that they scarcely make one turn and a half or two turns ; some larger sized make three turns and a half or four turns ; lastly, some very long are curled as many as eight or ten times. This is how the butterfly makes use of its trunk : When fluttering * " Sur les parties exterieures des papillons," tome i., p. 197. LEPIDOPTERA. 169 around a flower, it will very soon settle on or quite close to it. The trunk is then brought forward entirely or almost entirely unrolled ; very soon afterwards it is almost straightened, then directed down- wards, and plunged into the flower. Sometimes the insect draws it out a moment after, curves it, twists it a little, and sometimes even \ nnz of Lepidoptera. curls it partially up. Immediately it straightens it again, to plunge it a second time into the same flower. It repeats the same manoeuvre seven or eight times, and then flies on to another flower. This trunk, of which the butterfly makes such good use, is com- posed of two filaments more or less long, horny, concave in their interior surfaces, and fastened together by their edges. When cut I/O THE INSECT WORLD. transversely, one sees, according to Rdaumur,* that the interior is composed of three small rings. Consequently, there are three canals in the trunk : one central, the other two lateral (Fig. 138). Are all these three used to conduct the juice of flowers into the butterfly's body ? Reaumur has made some very interesting observations on this subject, by observing a moth which was sucking a lump of sugar whilst its portrait was being taken. " I held in one hand," says Reaumur, " a powerful magnifying glass, which I brought near to that part of the trunk I wished to examine ; I was some- times half a minute, or nearly a minute, without perceiving anything, after which I saw clearly a little column of liquid mounting quickly along the whole length of the trunk. Often this column appeared to be intersected by little balls, which seemed to be globules of air which had been drawn up with the liquid. "This liquid ascended thus during three or four seconds, and then ceased. At the end of an interval of a greater number of seconds, or sometimes after an interval as short, I saw Section of f iL'tfrfly-s Trunk some fresh lic l uid mounting up along the trunk, after Reaumur. ' But it was straight up the middle of the trunk that it seemed to ascend. " The Author of Nature has given to insects means of working, which, though very simple, we cannot divine, and which often we are not able even to perceive. Whilst I was observing the trunk of our butterfly, between the columns of liquid which I saw ascending, there were, but more rarely, times when I saw, on the contrary, liquid descending from the base of the trunk to the point. The descending liquid occupied half or two-thirds of the tube. It was no longer difficult to perceive how the butterfly is able to nourish itself on honey, the thickest syrup, and even the most solid sugar. The fluid it sends down is probably very liquid ; it drives against the sugar, moistens, and dissolves it. The butterfly pumps this liquid up again when it is charged with sugar, and conducts it along as far as the base of its trunk, and beyond it." The life of the perfect insect is generally very short. Like nearly all other insects, they die a soon as they have propagated their species. The female lays her eggs, which vary in shape, on the plant * Planche 9, Fig. IO, 5e Memoire, " Sur les parties exterieures des papillons." LEPIDOPTERA. I/I which is to nourish her progeny. The colour is also very various, and passes through all sorts of shades. At the moment they are laid, many are covered with a gummy substance, insoluble in water, which serves to stick them on the plant. In some species the mother lays her eggs on the trunks of trees, and covers them with down or with the hairs which clothe her abdomen, so as to preserve them from cold and damp. She may also hide them entirely under a whitish foamy substance. Some do not lay more than a hundred eggs ; others lay some thousands. To bring the history of the Lepidoptera to an end, it only remains for us to give a sketch of their classification, and to point out some species remarkable, either on account of their beauty or their utility. We see during the day butterflies flying in our gardens, in mea- dows full of flowers, or in the alleys of woods. Towards evening, at the sombre hour of twilight, the stroller is sometimes surprised to see pass near him large moths, with a heavy and unequal flight ; or, if we go into a garden on a beautiful calm summer's night, bearing a a light, we see a crowd of moths flying from all parts towards it. It is on account of these different hours at which the Lepidoptera show themselves, that naturalists for a long time divided them into diurnal, crepuscular, and nocturnal. This division was simple, con- venient, and seemed founded on Nature. Unfortunately, the night fliers of the old authors do not all fly by night : some species, classed by the old naturalists among the crepuscular, or nocturnal, show themselves in the very middle of the day, seeking their food in the hottest rays of the sun. In the regions near the poles they appear during the day, and in other countries they are more or less friends of the twilight. So as not to multiply methodical divisions, we will confine our- selves to classing the Lepidoptera into two sections. The first section contains those which fly during the day, which have club-shaped antennce, and which have, their Jour wings entirely free, and standing perpendicularly * when the insect is at rest. They are called Butterflies, or Rhopalocera. This section is divided into a number of families, which comprise many genera. We will content ourselves with calling the attention of the reader to some of the most remarkable of these groups, and to those species which, either on account of their beauty or abundance, strike, or ought to strike, the attention of every one. In the family of the Papilionidi, we will mention the genera * There are exceptions to this. ED. 172 THE INSECT WORLD. Papilio, to which belong the Swallow-tailed Butterfly (Papilio machaon], Papilio podalirius, &c., and Parnassius, of which we will notice Par- nassius Apollo, and Parnassius Mnemosyne. Fig. 139. Swallow-tailed Butterfly (Pajilio machaon). The swallow-tailed butterfly is found plentifully in the fens of Cambridgeshire, and Norfolk and Suffolk, and very commonly in the Fig. 140. Larva and Chrysalis of Papilio machaon. environs of Paris. It is seen from the beginning of May till towards the middle of June ; then from the end of July till September. It frequents gardens, woods, and, above all, fields of lucerne. It is easily taken when settled, particularly at sunset. LEPIDOPTERA. 173 This is one of the largest and the most beautiful of the European butterflies. The wings are variegated with yellow and black ; the eyes, antennae, and trunk are black. The body is yellow on the sides and underneath, and black above. The front wings have rounded edges ; the hind ones, on the contrary, are notched, and one of these notches is prolonged into a sort of tail. The first are black, Fig. 141. Papilio Alexanor. spotted and striped with yellow ; the second have their upper part and middle yellow, with some touches only of black. Near the margin is a broad black band, dusted with blue ; lastly, six yellow spots in the form of a crescent run along the border, and end in a magnificent eye of a reddish colour, bordered with blue. The caterpillar of this species is large, smooth, and of a beautiful light green, with a transverse black band on each ring. These bands are sprinkled with orange spots. It lives on the fennel, carrot, and other Umbelliferae. If teased, it thrusts from the first ring after 174 THE INSECT WORLD. the head a fleshy, orange-coloured tentacle. The chrysalis, attached to a stalk of grass, is sometimes light green, sometimes greyish. In the low Alps, on the plains near the environs of Digne and Barcelonette, is found in the months of May and July the Papilio Alexanor (Fig. 141), and in Corsica and Sardinians found the Papilio Fig. 142. The scarce Swallow-tailed Butterfly {Fapilio podah hospiton, a rare species, nearly related to our swallow-tailed butterfly, but which we will here content ourselves with mentioning. The Papilio podalirius (Fig. 142) is in form very analogous to Papilio niachaon. It is of a rather pale yellow colour, marked with black, as if singed. The lower wings have tails longer and narrower than those of the latter, and are magnificently ornamented with blue crescent-shaped spots and an orange-coloured eye bordered below with blue. This beautiful species is not rare at Montmorency, at He- Adam, and at St. Germain. It is said to have been taken in England, and is called the scarce Swallow-tail, but its capture is con- sidered as very questionable. It appears for the first time at the end LEPIDOPTERA. 1 75 of April, and for the second in July and August. The Parnassius Apollo (Fig. 143), is a beautiful butterfly, which appears in June and July, and is found commonly enough in the Alps, the Pyrenees, and and the Cevennes. Its wings are of a yellowish white. The upper part of the fore wings presents five nearly round black spots ; the base and the costa, or front edge, of these wings are sprinkled with black atoms. The upper part of the hind wings presents two eyes of a vermilion red, the inner border furnished with whitish hairs amply dotted with black, and marked towards the extremity with two black spots. The under part of the fore wings is very similar to the upper. Fig. 143. Parnassius Apollo. But the under part of the hind wings presents four red spots bordered by black, forming a transverse band near the base. The body is black, furnished with russety hairs, and the antennae white, with the club black. The larva of the Apollo lives on saxifrages. To affect its trans- formation it surrounds itself with a slight network of silk in which are confined one or more leaves. This caterpillar is thick, smooth, cylindrical, and covered with small slightly hairy warts, and orna- mented on the first ring with a fleshy tentacle in the shape of a Y. The chrysalis is conical, sprinkled over with a bluish efflorescence resembling the bloom on a plum. The Parnassius Mnemosyne is found in the month of June in the mountains of Dauphine, in Switzerland, Sicily, Hungary, Sweden, and in the Pyrenees. In the family of the Pieridi we will mention many species remarkable in different ways, such as Pieris crategi, the black-veined White, Pieris brassicce, the Cabbage Butterfly, Pieris napi, Pieris 1/6 THE INSECT WORLD. callidice, Anthocharis cardamines, the Orange-tip, Rhodocera (Gonep- teryx) rhamni, and Colias edusa, or Clouded-yellow. Pieris cratczgi is white both above and below ; the veins only of the wings are black, and become a little broader at the edge of the upper wings. These black veins on a rather transparent white ground make this butterfly resemble a gauze veil, hence its French name, le gaze. It flies in spring and summer in meadows and gardens, but is not generally common in England. In the first volume of his " Travels in the North of Russia," Pallas relates that he saw insects of this species flying in great numbers in the environs of Winofka, and that he at first took them for flakes of snow. The Pieris cratagi fixes itself at Fig. 144. Pieris brassicse. sunset on flowers, where it is easily taken by the hand. During the day, on the contrary, it is difficult to catch. The larva, black at first, afterwards assumes short yellow and white hairs, but it varies much. They live in companies, under a silky web, in which they pass the winter. The leaves of the hawthorn, the sloe, the cherry tree, and of many other fruit trees, serve them for food. The pupa, yellow or white, and sometimes of both colours with little stripes and spots ot black, is angular and terminated in front by a blunt point. The Pieris brassiccz (Fig. 144), or Cabbage Butterfly, is perhaps the commonest of all butterflies. From the beginning of spring till the end of autumn one sees it flying about everywhere, in the gar- dens, sometimes near and almost in the interior of towns. It is of a dull white, spotted and veined with black, and it can be seen at a long distance, when flitting from flower to flower, in a meadow or garden. And so children wage desperate war against this flying prey. The pursuit of the cabbage butterfly through the alleys of LEP1DOPTERA. 177 parks, along the outskirts of woods, or on the green turf of meadows, is the first joy and the first passion of children in the country. The caterpillar (Fig. 145) is of a yellowish green, or rather greenish yellow, with three yellow longitudinal stripes separated by little black points, from each of which springs a whitish hair. It lives in groups on the cabbages in gardens, and on many other Cruciferae. It is so voracious that it consumes in a day more than double its own weight, and, as it multiplies very quickly, commits great ravages in the vegetable garden. Its pupa (Fig. 145) is of an ashy white, spotted with black and yellow. The Pieris rapa, or Small White Butterfly, differs but little from the preceding except in size. The caterpillar, which lives on the cabbage, turnip, mignonette, nasturtium, &c., is green, with three yellow lines. It does not do these much harm. In France it is called le ver du caeur (the heart- worm), because it penetrates in between leaves pressed closely together. The Pieris napi (Fig. 146), the Green-veined White, is very like the two preceding, but the wings, the lower one especially, have underneath broad veins, or bands, of a greenish colour. The Pieris callidice, the wings of which are white spotted black, is common in the Alps of France, in Savoy and Switzerland, and in the Pyrenees. Its caterpillar lives near the regions of perpetual snow, on small cruciferous plants. The Orange-tips have, in the males, the extremity of the upper Fig. 146. Pieris napi. Fig. 147. Anthocharis cardamines. wings of a beautiful orange yellow. The rest of the wings is white in the only British species (Fig. 147), which is to be seen in meadows 1/8 THE INSECT WORLD. from the end of April till the end of May, and sulphur-coloured in some other species. One species, extremely common, and which appears with but short interruption from the beginning of spring till the end of autumn, is the Brimstone Butterfly (Rhodocera \Gonepteryoc\ rhamni). The wings are a lemon yellow, with an orange-coloured spot in the middle of each, and the front border terminated in a series of very small iron- coloured spots. The body of the butterfly is black with silvery hairs. Fig. 148. Thecla betuhe. The Colias edusa, or Clouded-yellow, so called from the colour ot the upper part of its wings, is not uncommon in meadows and fields in early autumn throughout Europe. The upper side of the wings is of a marigold yellow ; the upper ones having towards the middle a large spot of black. At the extremity of each wing is a broad black band, continuous in the case of the male, interrupted by yellow spots in the female. The back of the body is yellow ; the legs, as well as the antennae, rosy. The family of the Lyccznida comprises a great number of species, some of which we will mention. The Thecla, or Hair-streaks, which the French call Petits Porte- gttcues, on account of the tails which grace the hind margin of the hind wings, inhabit woods, their larvse feeding, according to the species, on the birch, the oak, the plum-tree, the bramble, &c. The Thecla betula (Fig. 148), or Brown Hair-streak, is somewhat rare in this country. LEPIDOPTERA. 179 The Purple Hair-streak (Thecla quercus, Fig. 149), which Geoffroy calls the " Porte-queue bleu a une bande blanche" is not rare in woods ; but it is very difficult to catch, as it flies nearly always by couples at Fig. 149. Thecla qercus. the tops of trees. We still further represent here the Black Hair- streak (Thecla fruni, Fig. 150), and the Green Hair-streak (Thecla rubi, Fig. 151). In the meadows are found the Copper Butterflies ; butterflies with Fig. 150. Thecla prunt wings of a bright, tawny colour, with black marks on the upper side. Such is the Polyommatus (Lyccena) phlceas (Fig. 152), which is very common from the end of May until late in the autumn. The upper M 2 i8o THE INSECT WORLD. part of the wing is coppery, spotted with black, the under side of a grey colour, sprinkled with small eyes, and bordered by a zone . 151. Thecla rub!. of tawny spots. Linnaeus counted forty-two little black eyes on the under side of the wings. We also figure Polyommatus (Lyccend) virgauretz (Fig. 153), and Fig. 152. Small Copper (Polyommatus [LycaMa] phlxas. Polyommatus (Lycana) gordius (Fig. 154), neither of which occurs in this country. In the meadows, the gardens, and the lucerne and clover fields, are found the charming Blue Butterflies, the wings on the upper 'side, in the majority of instances, blue in the case of the males, brown in the females. They comprise the genus Lyccena^ or, as it is frequently called, LEPIDOPTERA. l8l Polyommatus* though that name is now generally given to the ig- T S3- Polyommatus (Lycena) virgaureae. preceding. We will content ourselves here by giving drawings of a few species of the genus, namely, the Lyccena (Polyommatus] Corydon, Fig. 154. Polyommatus (Lycaena) gordius. or Blue Argus (Fig. 155), which is not uncommon wherever there is chalk, in May and August; the Lyc&na (Polyommatus) battus, or * It may not be out of place to remark that although both these generic names are applied, sometimes to the one, sometimes to the other of these genera, the 182 THE INSECT WORLD. Brown Argus (Fig. 156), which does not occur here; the Lycana (Polyommatus) represented the eggs and the cocoon. The moth has the abdomen yellowish under- neath, with little white tufts. Its wings are traversed by a white band, which is followed exteriorly by a line of a bright rose ; each wing is also marked by a lunula or crescent-shaped spot. In 1858 M. Guerin-Meneville presented to the Academic des vSciences of Paris the first moths and the first eggs laid in France of the Attacus Cynthia. This able entomologist demonstrated very soon afterwards ist, that the caterpillars of this insect can be reared in the open air, and with scarcely any cost for management ; 2ndly, that it produces two crops a year in the climate of Paris and the 246 THE INSECT WORLD. north of France ; 3rdly, that the cultivation of the Ailanthus, or the false Japan varnish tree, on which this insect lives, is easy even in the most sterile soil. M. Gu6rin-Meneville showed still further that ailantine, the d cocoons of Attacus (Uoml.yx) Cynthia. textile matter furnished by the cocoon of the Cynthia, is a sort of floss silk holding a middle place between wool and the silk of the mulberry-tree worm, and which, as it can be produced at scarcely any expense, would be very cheap, and would serve for the fabrication of what are called fancy stuffs, for which ordinary floss silk is now used. In 1862 M. Guerin-Me'neville sent in a Report to the Minister of LEPWOPTERA. 247 Agriculture on the progress of the cultivation of the Ailanthus, and of the breeding of the silkworm, which was reared in the open air on this tree. He mentions, in his Report, the rapid development of the cultivation of the tree in France, the great number of eggs of the Ailanthus silkworm sold, the foundation of a model silkworm nursery at Vincennes, and, this one great point gained, that they had found out the way of unwinding the silk from the cocoons of the Cynthia in one unbroken and continuous thread. Till then European industry had only succeeded in drawing from the cocoons of the Ailanthus silkworm a floss silk, composed of filaments more or less short, obtained by carding, and unable to produce, when twisted, anything better than floss, that is to say, refuse silk. It is to the Countess de Vernede de Corneillan, on the one hand, and to Doctor Forgemot on the other, that the merit is due of having obtained an unbroken thread of silk from the cocoon of Attacus Cynthia. A monograph on the Ailanthus silkworm appeared in 1866 under the title, " L'Ailante et son Bombyx, par Henri Givelet."* It is a complete account of all the results obtained up to the time, both as regards the rearing of the silkworm and also as regards the cultivation on a large scale of the Ailanthus, or false Japan varnish tree.t The Castor-oil Plant Silkworm (Attacus \Bombyx\ ricini} is a species very nearly akin to the Ailanthus worm, perhaps only a variety, and comes from India. The silk which it produces is very similar in every respect to that of the Cynthia. The rearing of this worm could never attain to any great importance in France, on account of the necessity there is of renewing the plantations of the castor-oil plant each year. It would, however, afford an additional source of income to the farmers in the south of France, who cultivate the castor-oil plant with a view to selling its seeds, which are much used in pharmacy. Nearly allied to the genus Attacus, which furnishes us with all these precious auxiliaries to the mulberry silkworm, are a great number of other species, both indigenous to Europe and exotic, mostly remarkable for their great size, and a few of which are common in this country. * In 8vo, avec plans et planches coloriees. Paris, 1866. t A work by M. Guerin-Meneville on the same subject, entitled, "Education des Vers a Soie de 1'Ailante et du Ricin," in I2mo., Paris, 1860, may also be consulted. [For a full account of successful experiments carried on in England, see Dr. Wallace's essay in The Transactions of the\Entomological Society of London, 3rd series, vol. v., pt. 2 ; Longmans and Co. ED.] 248 THE INSECT WORLD. Fig. 229 is the largest European moth, but never found farther north than the latitude of Paris. Its wings are brown, waved, and variegated with grey. Each of them has a large black eye-shaped spot, surrounded by a tawny circle, surmounted by one white semi- circle, and by another of a reddish hue, the whole completely enclosed Fig. 229.- Sat in a black circle. " These moths," says Geoffrey, " are very large ; they look as if they were covered with fur, and, when they fly, one is inclined to take them for birds." Saturnia pa vonia- major comes from a very large caterpillar, which is of a beautiful green, with tubercles of turquoise blue, each of which is surmounted by seven stiff divergent hairs. This caterpillar lives principally upon the elm, but it feeds also upon the leaves of the pear, plum, and other trees. It spins a brown cocoon, formed of a coarse silk of great strength. It is not until the following spring that it becomes a moth. LEI>1DOPTERA. 249 The Emperor Moth (Saturnia carpini, Fig. 230) much resembles the above, except in size. This species is common in England, and its green larva, covered with black or pink warts, from which spring hairs, as in the last, is by no means rare on heath in the autumn. It also feeds on bramble and other plants. Among the Attaci foreign to Europe, we must mention Atlas (Fig. 231), the expanse of whose wings exceeds four and a quarter Fig. 230. Emperor Moth (Saturnia carpiiti). inches. This magnificent moth, one of the largest known, comes from China. The family Bombycida comprises many species which we must not omit to mention. The Lackey (Bombyx neustrid) derives its name from the colour of the caterpillar, which has longitudinal lines of various colours, and a blue head. These caterpillars live together on a great number of our forest and garden trees, to which they do much damage. The moth (Fig. 232) has a brownish body, and wings of a more or less tawny yellow colour, with two darker lines on the front wings. The Procession Moth (Bombyx processioned) is a small greyish moth, the caterpillars of which live in numerous troops on oak trees, and devour the leaves at the moment of their development. In the 250 THE INSECT WORLD. evening these caterpillars come out of their common nest, and form a sort of procession ; hence their name Procession Moth. " I kept Fig. 232. The Lackey (Bomby.r neufiria). some for a little time in my house in the country," says Reaumur. " I brought an oak branch which was covered with them into my study, LEPIDOPTERA. 251 where I could much better follow the order and regularity of their march than I could have done in the woods. I was very much amused and pleased at watching them for many days. I hung the branch on which I had brought them against one of my window shutters. When the leaves were dried up, when they had become too hard for the jaws of the caterpillars, they tried to go and seek better food elsewhere. One set himself in motion, a second followed at his tail, a third followed this one, and so on. They began to defile and march up the shutter, but being so near to each other that the head of the second touched the tail of the first. The single file was throughout continuous ; it formed a perfect string of caterpillars of about two feet in length, after which the line was doubled. There two caterpillars marched abreast, but as near the one which preceded them as those who were marching in single file were to each other. After a few rows of our processionists who were two abreast, came the rows of three abreast ; after a few of these came those which were four abreast ; then there were those of five, others of six, others of seven, others of eight caterpillars. This troop, so well marshalled, was led by the first. Did it halt, all the others halted ; did it again begin to march, all the others set themselves in motion, and followed with the greatest precision. . . . That which went on in my study goes on every day in the woods where these caterpillars live When it is near sunset you may see one caterpillar coming out of any of the nests, by the opening which is at the top, which would hardly afford space for two to come out abreast. As soon as it has emerged from the nest, it is followed by many others in single file ; when it has got about two feet from the nest, it makes a pause, during which those who are still in the nest continue to come out ; they fall into their ranks, the battalion is formed ; at last the leader sets off marching again, and all the others follow him. That which goes on in this nest takes place in all the neighbouring nests ; all are evacu- ated at the same time." One part of Fig. 233 shows the arrangement of the caterpillars on coming out of the nest. These caterpillars are furnished with long hairs, slightly tufted, which come off with the greatest ease, and which if they penetrate into the skin, cause violent itching. In 1865 a number of the alleys of the Bois de Boulogne were shut up from the public in order to save them from this annoyance. These caterpillars construct a covering common to them all, in which they live, and transform themselves therein, each insect making for his own private use a small cocoon. This insect is said to have been found in England, but there is not sufficient evidence to admit it into our lists. 252 THE INSECT WORLr. Fig. 233. Larvee of the Proce ,sion Moth (JBcmfyx proctssionea). Fig. 234. The Vapourcr Moth (Qrgyia antiqua), male and female. The Orgyias comprise a great number of small species, of a dark colour, which do a great deal of damage to our forest trees. In Sep- LEPIDOPTERA. 253 tember and October the male of the Orgyia antiqua, with his tawny wings, may often be seen flying about the streets of London. The female (Fig. 234) is remarkable, as she has only the rudiments of wings, and only goes as far as the side of her cocoon. The cater- pillar of the Orgyia pudibimda, called also the Hop Dog, attacks almost every sort of tree. When the state of the atmosphere favours their propagation, they appear in fearful quantities, and cause the Fij. 235. Orgyia pudi'ouudu greatest havoc. During the autumn of 1828, in the environs of Phalsbourg, they were to be counted by millions. The extent of the woods laid waste was calculated at about fifteen hundred hectares. It is common in this country. Among the genus Liparis, the species of which are also very destructive to trees, AVC must mention the Brown-tailed Moth (Liparis chrysorrhcea, Fig. 236), a species by no means rare in England. The 254 THE INSECT WORLD. caterpillars live in quantities, on apple, pear, and elm trees, and destroy the plantations of the promenades of Paris. The females of this genus tear off the fur from the extremity of their abdomens to make a soft bed for their eggs, and to preserve them from the cold. And yet they are never to see their young, for they die after they have laid their eggs. An- other tribe of Bombycina contains species of a small size, which are remarkable from the habits of their caterpillars, which make, with foreign bodies, cases, in the interior of which they live and undergo their metamorphoses. The caterpillars of the genus Psyche live in a case composed of Fig. 236. Liparis chrysorrhosa. Fig. 237. Case of Psyche muscella. ^^WP Fig. 238. Psyche muscella. Fig. 239. Case of Pysche rubicolella. Fig. 240. Case of Psyche graminella. Fig. 241. Larva of Psyche graminella. Fig. 242. Psyche graminella. fragments of leaves, of bits of grass and straw, of small sticks of wood, or of little stones, stuck together, and intermixed with silky threads. VII. The Goat-moth (Cassus ligniperda). Larva, pupa, and perfect insect. i, 2. Perfect insect. 3. Pupa. 4. Larva. LEPIDOPTERA. 2$? We give a representation (in Figs. 237, 239, and 240) of the cases of the caterpillars of three different kinds. The females of these moths are completely destitute of wings, and resemble caterpillars. As a general rule they hardly ever leave their case. The males (Figs. 238, 242) are of a blackish grey, and fly very swiftly. The caterpillars of the genus Hepialus are difficult to observe, as they live in the interior of the roots of various vegetables. Such is the common Ghost Moth (Hepialus humidi], which sometimes causes the greatest damage. The type of the genus Zeuzera is Zeuzera (escufi, or Wood Fig. 243. Zeuzera aesculi. Leopard (Fig. 243). It has white wings with large blackish blue spots on the anterior, and small black spots on the posterior wings. The caterpillar, of a vivid yellow, spotted with black, lives in the interior of the trunks of a great many trees, principally the chestnut, the elm, the lime, and the pear tree. This moth, which is known also by the name of Coquette, is to be seen in the evening flying about the public gardens of Paris, and is not rare in England. The most celebrated species of the allied genus Cossus is the Wood- boring Goat Moth (Cossus ligniperdd), figured in the opposite plate. The moth has a heavy brownish body and greyish wings streaked with black. It is found in most parts of Europe. The caterpillar is of a reddish colour, as if it had on a leathern jerkin, and disgorges a liquid which is believed to soften ligneous fibres, and it lives in the interior 2$8 THE INSECT WORLD. of willows and other trees. It was on this caterpillar that Lyonnet made his admirable anatomical researches. Fig. 244. Larva of Dicranura vinula. Another tribe of Bombydna comprises some very strange cater- pillars, whose hindermost feet are changed into forked prolongations, which they move about in a threatening manner. These sort of fly- Fig. 245. Dicranura vinula. traps are perhaps meant to keep at a distance those insects which would lay their eggs upon the caterpillar's body. The caterpillars LEPIDOPTERA. 259 of Dicranura are of this kind. We give a representation of the caterpillar and the moth of the Puss Moth (Dicranura vinula, Figs. 244, 245), as also the moth of the Dicranura verbasci, the former of which is common in England, and the larva may be found 46. Dicranura verbasci. during the late summer and early autumn feeding on poplars and willows ; and of the caterpillar of Stauropus fagi, the Lobster Moth (Fig. 247), rare in France, whose appearance is strange indeed. The moths, on the contrary, have nothing about them remarkable. The Noctuina are a group of Lepidoptera of middling size, and generally found in woods, meadows, and gardens, > where their eater- Fig. 247. Larva of the Lobster Moth (Stauropus fagi). pillars have lived. They seldom fly till about sunset, or during the night. Their upper wings are of a dark colour, with spots in the middle of a particular shape. Their lower wings are of various colours, often whitish, sometimes red or yellow. R 2 260 THE INSECT WORLD. We give representations of some of the species of this group.* Noctua tegamon, Fig. 248 ; Noctua nebulosa, Fig. 249 ; Noctua musiva, Fig. 248. Noctua tegamon. Fig. 249- Noctua nebulosa. Fig 2