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Brux.; Hon. Mem. R. Irish Acad., Amer. Ethno]. Soc., Anthrop. Soc. Wash. (U. 8.). Brux., Fierenze, Anthrop. Verein Graz., Soc. Entom. de France, Soc. Géol. de Ja Suisse, and Soc. Helvét. des Sci. Nat. ; Mem. Amer. Phil, Soc, Philad. and Soc, d’Ethn. de Paris ; Corresp. Mem. Soc. Nat. des Sci.; Nat de Cherb., Berl. Gesell. fiir Anthrop.. Soc. Romana di Antrop., Soc. d’Emul. d’Abbeville, Soc. Cient. Argentina, Soc. de Géog. de Lisb., Acad. Nat. Sci. Philad., Numis. and Ant. Soc. Philad.; _ Amer. Entom. Soc. For. Assoc., Mem. Soc. d'Anthrop. de Baris ‘ For. Mem. Amer. Antiq. Soc. NEW YORK: D. APPLETON AND COMPANY, 1906. PREFACH. —+o1r—— Tus volume contains the record of various experiments made with ants, bees, and wasps during the past ten years. Other occupations and many interruptions, political and professional, have prevented me from making them so full and complete as I had hoped. My parliamentary duties, in particular, have absorbed most of my time just at the season of year when these insects can be most profitably studied. I have, there- fore, whenever it seemed necessary, carefully recorded the month during which the observations were made ; for the instincts and behaviour of ants, bees, and wasps are by no means the same throughout the year. My object has been not so much to describe the usual habits of these insects as to test their mental conditiov and_powers_of sense. vi PREFACE. Although the observations of Huber, Forel, McCook, and others are no doubt perfectly trustworthy, there are a number of scattered stories about ants which are quite unworthy of credence; and there is also a large class in which, although the facts may be correctly recorded, the inferences drawn from them are very questionable. I have endeavoured, therefore, by actual experiments which any one may, and I hope others will, repeat and verify, to throw some light on these interesting questions. The principal point in which my mode of experi- menting has differed from that of previous observers has been that I have carefully marked and watched particular insects ; and secondly, that I have had nests under observation for long periods. No one before had ever kept an ants’ nest for more than a few months. I have one now in my room which has been under constant observation ever since 1874, 7.e. for more than seven years.! * I may add that these ants are still (March 1882) alive and well, The queens at least are now eight years old, if not more. PREFACE. vil I had intended to make my observations principally on bees; but I soon found that ants were more con- venient for most experimental purposes, and I think they have also more power and flexibility of mind. They are certainly far calmer, and less excitable. I do not attempt to give anything like a full life- history of ants, but I have reproduced the substance of two Royal Institution lectures, which may serve as an introduction to the subject. Many of the facts there recorded wiil doubtless be familiar to most of my readers, but without the knowledge of them the ex- periments described in the subsequent chapters would scarcely be intelligible. I have given a few plates illustrating some of the species to which reference has been most frequently made ; selecting Lithography (as I was anxious that the figures should be coloured), and having all the species of ants drawn to one scale, although I was thus obliged in some measure to sacrifice the sharpness of outline, and the more minute details. I am indebted to Mr. viii PREFACE. Bates, Dr. GiNTHER, Mr. Kirsy, and Mr. WATERHOUSE, for their kind assistance in the preparation of the plates. As regards bees and wasps, I have confined myself for want of space to the simple record of my own observations. I am fully conscious that experiments conducted as mine have been leave much to be desired, and are scarcely fair upon the ants. In their native haunts and under natural conditions, more especially in warmer ¢limates, they may well be expected not only to manifest a more vivid life, but to develop higher powers. I think, however, that my volume will at least show the great interest of the subject, and the numerous problems which still remain to be solved. Hiau Ems, Down, Kent: Oototer 18, 1881 CONTENTS. CHAPTER I INTRODUCTION. Page Position of ants in the Animal Kingdom—Ants divided into three families—Number of species—Mode of observation— Nests—Mode of marking ants—Stages in life of ants—Egg, larva, pupa, imago—Length of life—Structure of ants— Head, thorax, abdomen, antenne, eyes, ocelli, mouth parts, legs, wings, sting—Origin of the sting—Character of ants— Wars among ants— Modes of fighting Queen ants— Workers —Different classes of workers—The honey ant—Soldiers— Origin of the soldiers—Division of labour—Habitations of ants—Communities of ants—Food—Enemies—Character— Tndustry—Games—Cleanliness : i ‘ « 1 CHAPTER II. FORMATION AND MAINTENANCE OF NESTS. foundation of new nests—Doubts on the subject—Views of Huber, Blanchard, Forel, St. Fargeau, Ebrard—Experiments with queens— Foundation of a nest of Myrmica by two queens—Adoption of queens—Fertility of workers—Eggs laid by fertile workers always produce males—Queens seldom produced in captivity—Origin of difference between queens and workers—Longevity of ants—Arrangement of chambers in a nest—Division of labour—The honey ant . 30 zx CONTENTS. CHAPTER III. ON THE RELATION OF ANTS 10 PLANTS. racy Flowers and insects—Ants not so important in relation to flowers as bees, but not without influence—Ants seldom promote cross-fertilisation, and hence injurious to flowers— Modes by which they are excluded — Belt — Kerner — Aquatic plants — Moats — Dipsacus — Slippery surfaces— Gentian, snowdrop, cyclamen — Concealment of honey— Antirrhinum, Linaria, Campanula, Ranunculus, Lamiwn, Primula, Geranium, &c.—Protection of honey by thickets of spines or hairs—Protection by viscid secretions— The Honey Ant of Texas, MaRKEL,F. . . Beit. zur Kenntniss der unter Ameisen leben. den Insecten. Germar’s Zeit. Ent., 1841. Mayr, Dr. G. L. . Europ. Formiciden. - * « Leben und Wirken der einh. Ameisen. MEINERT, F. . . Bidrag til de Danske Myrers Naturhisturie. Kiébenhaven, Dansk. vid. Selsk., 1861. MEYER, J 5 Ueber conconlose Ameisenpuppen. Stettin Ent. Zeit., 1854. MUuurr, P.W.J. . Beitriige zur Naturgeschichte der Gattung Claviger. Germar’s Mag. de Zool., 1818. ORMEROD, E. L. - Natural History of Wasps. RAMBERT, M. . - Moeurs des Fourmis. RoBEet, E. - . Observations sur les Mceurs des Fourmis, Ann. des Sci. Nat , 1842. RoGeEr, J. : Beit. zur Kennt. der Ameisenfauna der Mittelmeerlinder. Berlin. Ent. Zeit., 1857. St. FARGEAU, LEPELETIER. Hist. Nat. des Hyménoptéres, SAUNDERS, EDwarp Brit. Heterogyna and Foss. Hymenoptera. Trans, Ent. Soc., 1880. Savacez,T.8. . On the Habits of Driver Ants. Trans, Ent. Soc., 1847. SCHENK, Professor . Beschr. Nassau. Ameisenarten, Stettin. Ent, Zeit., 1853. SIEBOLD, C, T. von, Ueber das Stimm. und GehGrorgan der Or- thopteren, Weissmann’s Arch., 1844, SMITH, F. Cat. of Brit. Foss. Hymenoptera, + . . Essay on British Formicide. Trans, Ent. Soc., N.S. vol. iii. p. 98. avKeEs, Col, . Account of Pheidole providens, Trans. Ent. Soc., 1836. WEsMAEL, C Sur une nouv. Espéce de Fourmi du Mexique. Bull. de l’Acad. de Sci. de Bruxelles, 1838. Werstwoop, J 0. . Modern Classification of Insects. " . Obs. on Typhlopone. Ann. Mag. Nat. Hist. 1841. fan ANTS, BEES, AND WASPS. CHAPTER INTRODUCTION. THe Anthropoid apes no doubt approach nearer to man in bodily structure than do any other animals; but when we consider the habits of Ants, their social organisation, their large communities, and elaborate habitations; their roadways, their possession of domestic animals, and even, in some cases, of slaves, it must be admitted that they have a fair claim to rank next to man in the scale of intelligence. They present, more- over, not only a most interesting but also a very ex- tensive field of study. They are divided into three families: the Formicide, Poneride, and Myrmicide, eomprising many genera and a large number of species. (n this country we have rather more than thirty kinds ; but ants become more numero.s in species, as well as individuals, in warmer countries, and more than a 2 NUMBER OF SPECIES. thousand species are known. Even this large number 1s certainly far short of those actually in existence.! I have kept in captivity about half of our British gpecies of ants, as well as a considerable number of foreign forms, and for the last few years have generall; had from thirty to forty communities under observation. After trying various plans, T found the most con- venient method was to keep them in nests consisting of two plates of common window glass, about ten inches square, and at a distance apart of from 1, to } of an inch (in fact just sufficiently deep to allow the ants freedom of motion), with slips of wood round the edges, the intermediate space being filled up with fine earth. If the interval between the glass plates was too great, the ants were partly hidden by the earth, but when the distance between the plates of glass was properly regulated with reference to the size of the ants, they were open to close obser- vation, and had no opportunity of concealing them- selves. Ants, however, very much dislike light in their nests, probably because it makes them think themselves insecure, and I always therefore kept the nests covered over, except when under actual ' Ihave had some doubt whether I should append descriptions of the British species. On the whole, however, I have not thought it necessary to do so. They are well given in various entomological works: for instance, in Smith’s Catalogue of British Fossorial Hymenoptera; Saunders’ Synopsis of British Heterogyna; and in Mayr’s Die Europiischen Formiciden, all of which are cheap and easily procurable. I have, however, given figures of the principal species wiih which I have worked, MODE OF OBSERVATION. 3 observation. I found it convenient to have one side of the nest formed by a loose slip of wood, and at one corner I left a small door. These glass nests I either kept in shallow boxes with loose glass covers resting on baize, which admitted enough air, and yet was im- pervious to the ants; or on stands surrounded either by water, or by fur, with the hairs pointing downwards. Some of the nests I arranged on stands, as shown in Fie. 1. | B AB fig. 1. A A is an upright post fixed on a base BB. CC is a square platform of wood round which runs a ditch of water. Above are six nests, D, each lying on a platform E, which could be turned for facility of observation, as shown in the dotted lines D’ and FE’, Thus the ants had a considerable range, as they could wander as far as the water ditch. The object of having the platform C C larger than the supports of the nests 4 ARTIFICIAL NEST was that if the ants fell, as often happened, they were within the water boundary, and were able to return home. This plan answered fairly well, and saved space, but it did not quite fulfil my hopes, as the ants were so pugnacious, that I was obliged to be very careful which nests vere placed on the same stand. Of course it was impossible to force the ants into these glass nests. On the other hand, when once the right way is known it is easy to induce them to go in. When I wished to start a new nest I dug one up, and brought home the ants, earth, &c., all together. I then put them over one of my artificial nests, on one of the platforms surrounded by a moat of water. Gra- dually the outer earth dried up, while that between the two plates of glass, being protected from evapo- ration, retained its moisture. Under these circum- stances the ants found it more suitable to their requirements, and gradually deserted the drier mould outside, which I removed by degrees. In the earth between the plates of glass the ants tunnelled out passages, chambers, &c. (fig. 2)¥ varying in form ac- cording to the circumstances and species. Even between the plates of glass the earth gradu- ally dried up, and I had to supply artificial rain from time to time. Occasionally also I gave them an alto- gether new nest. They seem, however, to get attached tc their old homes, and I have one community which has i hahited the same glass case ever since 1874, It is hardly necessary to say that, the individual DIFFERENCES IN HABITS, 5 ants Ielonging to the communities placed on the stands just described, knew their own nests perfectly well. These nests gave me special facilities for observing the internal economy of ant life. Another main diffe- rence between my observations and those of previous naturalists has consisted in the careful record of the actions of individual ants. The most convenient mode of marking them was, I found, either with a small dab of paint on the back, or, in the case of bees or wasps, by snipping off a fragment at the extremity of the wing. This, I need hardly say, from the structure of the wing, gave the insect no pain; in fact, as it is only necessary to remove a minute portion, not sufficient to make any difference in their flight, they seemed searcely to notice it. I never found any difficulty in painting bees or wasps; if they are given a little honey they become so intent that they quietly allow the paint to be applied. Of course too much muat not be put on, and care must be taken not to tonch the wings or cover up the spiracles. Ants require somewhat more delicate treatment, but with a little practice they could also be marked without any real difficulty. No two species of Ants are identical in habits; and, on various accounts, their mode of life is far from easy to unravel. In the first place, most of their time is passed underground: all the education of the young, for instance, is carried on in the dark. Again, ants are essentially gregarious; it is in some cases difficult to 6 STAGES IN THE LIFE OF ANTS—EGGS. keep a few alive by themselves in captivity, and at any rate their habits under such circumstances are entirely altered. If, on the other hand, a whole community is kept, then the greater number introduces a fresh element of difficulty and complexity. Moreover, within the same species, the individuals seem to differ in character, and even the same individual will behave very differently under different circumstances. Al- though, then, ants have attracted the attention of many of the older naturalists,—Gould, De Geer, Reaumur, Swammerdam, Latreille, Leuwenhoeck, Huber,—-and have recently been the object of interesting obser- vations by Frederick Smith, Belt, Moggridge, Bates, Mayr, Emery, Forel, McCook, and others, they still present one of the most promising fields for observation and experiment. The life of an ant falls into four well-marked periods—those of the egg, of the larva or grub, of the pupa or chrysalis, and of the perfect insect or imago. The eggs are white or yellowish, and somewhat elon- gated. They are said to hatch about fifteen days after being laid. Those observed by me have taken a month or six weeks. ‘The larva of ants (Pl. V. fig. 3), like those of bees md wasps, are small, white, legless grubs somewhat conical in form, being narrow towards the head. They are carefully tended and fed, being carried about from chamber to chamber by the workers, probably in order to secure the most suitable amount of warmth LARVA—PUPA. ? and moisture. I have observed, also, that they are very often assorted according to age. It is sometimes very curious in my nests to see them arranged in groups according to size, so that they remind one of a school divided into five or six classes. As regards the length of life of the larve, Forel supposed! that those of Tapinoma matured the quickest, and were full-grown in about six or seven weeks. Some of Myrmica ruginodis, however, ob- served by me, turned into pupe in less than a month. In other cases the period is much longer. In certain species, Lasius flavus, for instance, some of the larva live through the winter. When full grown they turn into pupe (PI. V. fig. 4), sometimes naked, sometimes covered with a silken cocoon, constituting the so-called ‘ant-eggs.’ We do not yet understand why some larvee spin cocoons, while others remain naked. Asa general rule, the species which have not a sting, spin a cocoon, while those which have, are naked. Latreille was the first to observe that in one species (F. fusca) the pup sometimes spin a cocoon, and sometimes remain naked. The reason for this difference is still quite unknown. After remaining some days in this state they emerge as perfect insects In many cases, however, they would perish in the attempt, if they were not assisted ; and it is very pretty tc see the older ants helping them to extricate them- » Les Fourmis de la Suisse, p. 420. 8 PUPA—IMAGO. selves, carefully unfolding their legs and smoothing out the wings, with truly feminine tenderness and delicacy. Our countryman Gould was the first to observe, and the fact has since been fully confirmed by Forel, that the pup are unable to emerge from the cocoons without the assistance of the workers. The ants generally remain from three to four weeks in this condition. In the case of ants, as with other insects which pass through similar metamorphoses, such as bees, wasps, moths, butterflies, flies, and beetles, &c., the larval stage is the period of growth. During the chrysalis stage, though immense changes take place, and the organs of the perfect insect are more or less rapidly developed, no food is taken, and there is no addition to the size or weight. The imago or perfect insect again takes food, but does not grow. The ant, like all the insects above named, is as large when it emerges from the pupa as it ever will be; excepting, indeed, that the abdomen of the females sometimes increases in size from the de- velopment of the eggs. We have hitherto very little information as to the length of life in ants in the imago, or perfect, state. So far, indeed, as the preparatory stages are concerned, there is little difficulty in approximately ascertaining the facts; namely, that while in summer they take only a few weeks; in some species, as our small yellow meadow ants, the autumn larve remain with compara- e LENGTH OF LIFE. 9 tively little change throughout the winter. It is much more difficult to ascertain the length of life of the perfest insect, on account of their gregarious habits, and the difficulty of recognising individual ants. I have found, however, as we shall presently see, that their life is much longer than has been generally supposed. It is generally stated in entomological works that the males of ants die almost immediately. No doubt this is generally the case. At the same time, some males of Myrmica ruginodis, which I isolated with their mates in August 1876, lived until the following spring ; one of them till May 17. It has also been the general opinion that the females lived about a year. Christ! indeed thought they might last three or even four seasons, but this was merely a suggestion, and Forel expressed the general opinion when he said, ‘Je suis persuadé qu’en automne il ne reste presque plus que les ouvriéres écloses pendant le courant de J’été. The average life of a queen is also, he thinks, not more than twelve months. I have found, however, that the life of the queens and workers is much longer than had been sup- posed. I shall give further details in a subsequent chapter, but I may just mention here that I kept a queen of Yormica fusca from December 1874 till August 1888, when she must have been nearly fifteen years old, and of course may have been more. She 1 Naturgeschichte der Insekten. 3 10 STRUCTURE OF ANTS. attained, therefore, by far the greatest age of any insect on record. I have also some workers which I have had since 1875. The body of an ant consists of three parts: the head, thorax, and abdomen. The head bears the principal organs of sense, and contains the brain, as the anterior portion of the nervous system may fairly be called. The thorax, supporting the legs and, when they are present, the wings, contaius the principal muscles of locomotion. The abdomen contains the stomach and intestines, the organs of reproduction, the sting, &c. Returning to the head: the antenne consist of a short spherical basal piece, a long shaft, known as the scape, and a flagellum of from six to seventeen (gen- erally, however, from ten to thirteen) short segments, the apical ones sometimes forming a sort of club. The number of segments is generally different in the males and females. The eyes are of two kinds. Large compound eyes, one on each side of the head; and ocelli, or so-called simple eyes. The compound eyes consist of many facets. The number differs greatly in different species, and in the different sexes, the males generally having the greatest number. Thus, in Formica pratensis there are, according to Forel, in the males about 1,200 in each eye, in the fertile females between 800 and 900, in the workers about 600. Where the workers vary in size 1 Having reference to the facts stated on page 37, this is a result of great physiological interest. THE HEAD. ll they differ also in the number of facets. Thus, aguin following the same authority, the large workers of Camponotus ligniperdus have 500, the smaller ones only 450; while in the Harvesting ant (Atta barbara) the contrast is even greater, the large specimens having 230, the small ones only from 80 to 90. The ordinary workers have in Polyergus rufescens about 400; in Lasius fuliginosus, 200; in Tapinoma erra- ticum, 100; in Plagiolepis pygmca, 70 to 80; in Lasius flavus, about 80; in Bothriomyrmex meri- dionalis, 55; in Strongylognathus testaceus, Stenamma Westwoodti, and Tetramorium caspitum, about 45 ; in Pheidole pallidula, about 30; Myrmecina La- treillei, 15; Solenopsis fugax, 6 to 9; while in Ponera contracta there are only from 1 to 5; in Eciton only 1; and in Typhlopone the eyes are altogether wanting. The number of facets seems to increase rather with she size of the species than with the power of vision. The ocelli are never more than three in number, disposed in a triangle with the apex in front Some- times the anterior ocellus alone is present. In some species the workers are altogether without ocelli, which, however, are always present in the queens and in the males. The mouth parts are the labrum, or upper lip; the first pair of jaws or mandibles ; the second pair of jaws or maxille, which are provided with a pair of palpi, or feelers; and the lower lip, or labium, also bearing a pair of palpi 12 THE THORAX. The thorax is generally considered to consist, as in other insects, of three divisions —the prothorax, meso- thorax, and metathorax. I have elsewhere, Lowever, given reasons into which I will not at this moment enter, for considering that the first abdominal segment has in this group coalesced with the thorax. The thorax bears three pairs of legs, consisting of a coxa, trochanter, femur, tibia and tarsus, the latter composed of five segments and terminating in a pair of strong claws. In the males and females the meso- and meta- thorax each bear a pair of wings, which, however, are stripped off by the insects themselves soon after the marriage flight. The workers never possess wings, nor do they show even a rudimentary representative of these organs. Dr. Dewitz has pointed out that the full-grown larve of the workers possess well-developed ‘ imaginal disks,’ like those which, in the males and females, develope into the wings. These disks, during the pupal life, gradually become atrophied, until in the perfect insects they are represented only by two strongly chitinised points lying under the large middle thoracic stigmas. No one unacquainted with the original history of these points would ever suspect them to be the rudi- mentary remnants of ancestral wings.! The thorax also bears three pairs of spiracles, o1 breathing holes. " Zeit. f. wiss. Zool., vol. xxviii. p. B58 THE ABDOMEN, 13 The abdomen consists of six segments, in the queens and workers, that is to say in the females, and seven in the males. The first segment, as a general rule, in the Formicide forms a sort of peduncle (known as the scale or knot) between the metathorax and the remainder of the abdomen. In the Myrmicide two segments are thus detached from the rest. The Poneride form, as regards the peduncle, and in some other respects, an intermediate group between the Formicide and the Myrmicide. The second abdo- minal segment is contracted posteriorly, but not so much so as to form a distinct knot. The form of the knot offers in many cases valuable specific characters. I have sometimes been tempted to correlate the existence of a second knot among the Myrmicide with their power of stinging, which is wanting in the For- micide. Though the principal mobility of the abdomen is given in the former, as in the latter, by the joint between the metathorax and the knot, still the second segment of the peduncle must increase the flexibility, which would seem to be a special advantage to those species which have a sting. It must indeed be admitted that CEcophylla' has a sting, and yet only one knot; but this, of course, does not altogether negative my suggestion, which, however, I only throw out for consideration » Proo. Linn. Soe., vol. v. p. 10%. 14 THE STING. The knot is provided with a pair of spiracles, which are situated, as Forel states, in the front of the segment, and not behind, as supposed by Latreille. In most entomological works it is stated that the Myrmicide have a sting, and that, on the contrary, the Formicide do not possess one. The latter family, indeed, possess a rudimentary structure representing the sting, but 1t seems merely to serve as a support for the poison duct. Dr. Dewitz, who has recently pub- lished! an interesting memoir on the subject, denies that the sting in Formicide is a reduced organ, and considers it rather as in an undeveloped condition. The ancestors of our existing Ants, in his opinion, had a large poison apparatus, with a chitinous support like that now present in Formica, from which the formidable weapons of the bees, wasps, and Myrmicide have been gradually developed. I confess that I am rather disposed, on the contrary, to regard the con- dition of the organ in Formica as a case of retrogres- sion contingent upon disuse.» I find it difficult to suppose that organs—so complex, and yet so similar— as the stings of ants, bees, and wasps, should have been developed independently, Any opinion expressed by M. Dewitz on such a subject is, of course, entitled to much weight; never- theless there are some general considerations which seem to me conclusive against his view. If the sting 1 Zeit. f. wiss. Zool., vol. xxviii. p. 527, * This view has subsequently been adopted by Dr. Beyer, Jena Zeit, 1890. ORIGIN OF THE STING, 18 of Formica represents a hitherto undeveloped organ, then the original ant was stingless, and the present stings of ants have an origin independent of that belonging to the other aculeate Hymenoptera, such as bees and wasps. These organs, however, are so complex, and at the same time so similarly constituted, that they must surely have a common origin. Whether the present sting is derived from a leaf-cutting instru- ment, such as that from which the sawfly takes its name, I will at present express no opinion. Dr. Dewitz him- self regards the rudimentary traces of wings in the larve of ants as the remnants of once highly-developed organs ; why, then, shou'd he adopt the opposite view with reference to the rudimentary sting? On the whole, I must regard the ancestral ant as having pos- sessed a sting, and consider that the rudimentary con- dition of that of Formica is due to atrophy, perhaps through disuse. On the other hand, it is certainly, at first sight, diffi- cult to understand why ants, having once acquired a sting, should allow it to fall into desuetude. There are, however, some considerations which may throw a certain light on the subject. The poison glands are much larger in Formica than in Myrmica. Moreover, some species have the power of ejecting their poison to a consider- able distance. In Switzerland, after disturbing a nist of Formica rufa, or some nearly allied species, I have found that a hand held as much as 18 inches above the ants was covered with acid. But even when the poison 16 THE POISON OF ANTS, is not thus fired at the enemy from a distance, there are two cases in which the aculeus might be allowed to fall into disuse. Firstly, those species which fight with their mandibles might find it on the whole most convenient to eject the poison (as they do) into the wounds thus created. Secondly, if the poison itself is so intensified in virulence as to act through the skin, a piercing instrument would be of comparatively small advantage. I was amused one day by watching some specimens of the little Cremastogaster sordidula and the much larger Formica cinerea. The former were feeding on some drops of honey, which the Formicas were anxious to share, but the moment one approached, the little Cremastogasters simply threatened them with the tip of their abdomen, and the Formicas immediately beat a hasty retreat. In this case the comparatively large Formica could certainly have had nothing to fear from physical violence on the part of the little Cremastogaster. Mere contact with the poison, however, appeared to cause them considerable pain, and generally the threat alone was sufficient to cause a retreat. However this may be, in their modes of fighting, different species of ants have their several peculiarities. Some also are much less military than others. “ Myr- mecina Latreillii, for instance, never attack, and scarcely even defend themselves. Their skin is very hard, and they roll themselves into a ball, not defend- ing themselves even if their nest is invaded ; to pre- MODES OF FIGHTING. 17 vent which they make the entrances small, and often station at each a worker, who uses her head to stop the way. The smell of this species is also, perhaps, a protection. Tetramorium cespitum has the habit of feigning death. This species, however, does not roll itself up, but merely applies its legs and antlenne closely to the body. Formica rufa, the common Horse ant, attacks in serried masses, seldom sending out detachments, while single ants scarcely ever make individual attacks. They rarely pursue a flying foe, but give no quarter, killing as many enemies as possible, and never hesi- tating, with this object, to sacrifice themselves for the common good. Formica sanguinea, on the contrary, at least in their slave-making expeditions, attempt rather to terrify than to kill. Indeed, when invading a nest, they do not attack the flying inhabitants unless these are attempting to carry off pup, in which case the F. sanguineas force them to abandon the pupa. When fighting, they attempt to crush their enemies with their mandibles. Formica exsecta is a delicate, but very active species. They also advance in serried masses, but in close quarters they bite right and left, dancing about to avoid being bitten themselves. When fighting with larger species they spring on to their backs, and then seize them by the neck or by an antenna They also have the instinct of acting together, three 18 DIFFERENT CLASSES OF INDIVIDUALS, or four seizing an enemy at once, and then pulling different ways, so that she on her part cannot get at any one of her foes. One of them then jumps on her back and cuts, or rather saws, off her head. In battles between this ant and the much larger F. pra- tensis, many of the F. exsectas may be seen on the backs of the F. pratensis, sawing off their heads from behind. The species of Lasius make up in numbers what they want in strength. Several of them seize an enemy at once, one by each of her legs or antenna, and when they have once taken hold they will suffer themselves to be cut in pieces rather than leave go. Polyergus rufescens, the celebrated slave-making or Amazon ant, has a mode of combat almost peculiar to herself. The jaws are very powerful, and pointed. If attacked—if, for instance, another ant seizes her by a leg—she at once takes her enemy’s head into her jaws, which generally makes her quit her hold. If she does not, the Polyergus closes her mandibles, so that the points pierce the brain of her enemy, paralysing the nervous system. The victim falls in convulsions, setting free her terrible foe. In this manner a com- paratively small force of Polyergus will fearlessly attack much larger armies of other species, and suffer themselves scarcely any loss. Under ordinary circumstances an ants’ nest, like a beehive, consists of three kinds of individuals: workers, or imperfect females (which constitute the THE HONEY ANT. 19 great majority), males, and perfect females. There are, kowever, often several queens in an ants’ nest; while, as we all know, there is never more than one queen mother ina hive. The queens of ants are pro- vided with wings, but after a single flight they tear them off, and do not again quit the nest. In ad- dition to the ordinary workers there is in some species a second, or rather a third, form of female. In almost any ants’ nest we may see that the workers differ more or less in size. The amount of difference, however, depends upon the species. In-Lasius niger, the small brown garden ant, the workers are, for instance, much more uniform than in the little yellow meadow ant, or in Atta barbara (Pl. II. figs. 1 and 2), where. some of them are much more than twice as large as others. But in certain ants there are differences still more re- markable. Thus, ina Mexican species, Myrmecocystus,' besides the common workers, which have the form of ordinary neuter ants, there are certain others in which the abdomen is swollen into an immense sub-diapha~ nous sphere. ‘These individuals are very inactive, and principally as living honey-jars. Ihave described in a subsequent page a species of Camponotus (Pl. IV. fig. 1) from Australia, which presents us with the same remarkable phenomenon. In the genus Pheidole (PI. II. figs. 3 and 4), very common in southern Euroye, there are also two distinct forms without any interme- diate gradations; one with heads of the usual propor- + Wesmael, Bull. Acad. Rey. Bruwelles, vol. v. p. 771. 20 WORKERS—SOLDIERS. tion, and a second with immense heads provided with very large jaws. This differentiation of certain indi- viduals so as to adapt them to special functions seems to me very remarkable; for it must be remembered that the difference is not one of age or sex. The large- headed individuals are generally supposed to act as soldiers, and the size of the head enables the muscles which move the jaws to be of unusual dimensions; but the little workers are also very pugnacious. Indeed, in some nests of Pheidole megacephala, which I had for some time under observation, the small workers were quite as ready to fight as the large ones. Again, in the genus Colvbopsis Emery discovered that two ants, then supposed to be different species, and known as Colobopsis truncata and C. fuscipes, are really only two forms of one species. In this case the entrance to the nest is guarded by the large-headed form, which may therefore fairly be called a soldier. Savage observed among the Driver Ants, where also there are two kinds of workers, that the large ones arranged themselves on each side of the column formed by the small ones. They acted, he says, evidently the part of guides rather than of guards. At times they place ‘their abdomen horizontally on the ground, and laying hold of fixed points with their hind feet (which together thus acted as a fulerum), elevate the anterior portion of their bodies to the highest point, open wide their jaws, and stretch forth their antennz, which for the most part were fixed, as if in the act of listening FIVE KINDS OF INDIVIDUALS IN SAUBA. 21 and watching for approaching danger. They would occasionally drop their bodies to the ground again, run off to one side, and fiercely work their jaws and antenne, as if having detected some strange sounds in the dis- tance. Discerning nothing, they would quickly return to their posts and resume their positions, thus acting as scouts,”! The same thing has been noticed by other natu- ralists. Bates, for instance, states that in the marching columns of Eciton drepanophora the large-headed workers ‘all trotted along empty-handed and outside the column, at pretty regular intervals from each other, like subaltern officers in a marching regiment... . I did not see them change their position, or take any notice of their small-headed comrades;’ and he says that if the column was disturbed they appeared less pugnacious than the others. In other species, however, of the same genus, Eciton vastator and E. erratica, which also have two distinct kinds of workers, the ones with large heads do appear to act mainly as soldiers. When a breach is made in one of their covered ways, the small workers set to work to repair the damage, while the large-headed ones issue forth in a menacing manner, rearing themselves up and threatening with their jaws. In the Sauba Ant of South America (4codoma cephalotes), the complexity is carried still further; 1 Rev. T. S. Savage on the ‘Habits of the Driver Anta,’ Trane. Ent. Soe., vol v. p. 12. 22 ORIGIN OF THE SOLDIERS. Lund! pointed out that there were two different Lunds of workers, but Bates has since shown that there are in this species no less than five classes of individuals, ramely: 1. Males. 2. Queens. 3. Small ordinary workers (PI. III. fig. 2). 4. Large workers (Pl. ILI. fig. 1), with very large hairy heads. 5. Large workers, with large polished heads. Bates never saw either- of these two last kinds do any work at all, and was not able to satisfy himself as to their functions. They have also been called soldiers, but this is obviously a misnomer—at least, they are said never to fight. Bates suggests? that they may ‘serve, in some sort, as passive instruments of protection to the real workers. Their enormously large, hard, and indestructible heads may be of use in protecting them against the attacks of insectivorous animals. They would be, on this view, a kind of piéces de resistance, serving as a foil against onslaughts made on the main body of workers.’ This does not, I confess, appear to me a probable explanation of the fact, aad on the whole it seems that the true function of these large-headed forms is not yet satisfactorily explained. The question then arises whether these different kinds of workers are produced from different eggs, I am disposed to concur with Westwood in the opinion® ‘that the inhabitants of the nest have the instinct so to modify the circumstances producing this 1 Ann. des Sct. Nat. 1831, p. 122. ? Loo. cit. p. 81. * Modern Classification of Insects, vol. ii. p. 226. DIVISION OF LABOUR. 28 svate of imperfection, that some neuters shall exhidit characters at variance with those of the common kind.’ This, indeed, credits them with a very remarkable instinct, aud yet I see no more probable mode of ac- counting for the facts. Moreover, the exact mode by which the differences are produced is still entirely unknown. M. Forel, in his excellent work on ants, has pointed out that very young ants devote themselves at first to the care of the larve and pupe, and that they take no share in the defence of the nest or other out-of-door work until they are some days old. This seems natural, because at first their skin is comparatively soft; and it would clearly be undesirable for them to undertake rough work or run into danger until their armour had had time to harden. There are, however, reasons for think- ing that the division of labour is carried still further. I do not allude merely to those cases in which there are completely different kinds of workers, but even to the ordinary workers. In L. flavus, for instance, it seems probable that the duties of the small workers are somewhat different from those of the large ones, ‘though no such division of labour has yet been detected. I shall have to record some further observations point- ing in the same direction. The nests of ants may be divided into several classes. Some species, such as our common Horse ant (Formica rufa), collect large quantities of materials, such as bits of stick, fir leaves, &c., which they heap 24 HABITATIONS OF AN'S. up into conical masses. Some construct their nests of earth, the cells being partly above, partly below, the natural level. Some are entirely underground, others eat into the trunks of old trees. In warmer climates the variations are still more numerous. Formica bispinosa, of Cayenne, forms its nest of the cottony matter from the capsules of Bombax. Sykes has described! a species of Myrmica which builds in trees and shrubs, the nest consisting of thin leaves of cow-dung, arranged like tiles on the roof of a house; the upper leaf, however, covering the whole. In some cases the nests are very extensive. Bates meutions that while he was at Para an attempt was made to destroy a nest of the Sauba ants by blowing into it the fumes of sulphur, and he saw the smoke issue from a great number of holes, some of them not less than seventy yards apart. A community of ants must not be confused with an ant hill in the ordinary sense. Very often indeed a community has only one dwelling, and in most species seldom more than three or four. Some, however, form numerous colonies. M. Forel even found a case in which one nest of F. exsecta had no less than two hundred colonies, and occupied a circular space with a radius of nearly two hundred yards. Within this area they had exterminated all the other ants, except a few neste of Tapinoma erraticum, which survived, thanks to their great agility. In these cases the number of ' Trans. Ent. Soc., vol. i COMMUNITIES OF ANTS, 26 ants thus associated together must have been enor- mous. Even in single nests Forel estimates the numbers at from five thousand to half a million. Ants also make for themselves roads, These are not merely worn by the continued passage of the ants, as was supposed by Christ, but are actually prepared by the ants, rather however by the removal of obstacles, than by any actual construction, which would indeed not be necessary, the weights to be carried being so small. In some cases these roadways are arched over with earth, so as to form covered ways.’ In others, the ants excavate regular subterranean tunnels, sometimes}: of considerable length. The Rev. Hamlet Clark even assures us that he observed one in South America, which passed under the river Parahyba at a place where it was as broad as the Thames at London Bridge. I confess, however, that I have my doubts as to this case, for I do not understand how the continuity of the tunnel was ascertained. The food of ants consists of insects, great numbers of which they destroy; of honey, honeydew, and fruit : indeed, scarcely any animal or sweet substance comes amiss to them. Some species, such, for instance, as the small brown garden ant (Lasius niger, Pl. I. fig. 1), ascend bushes in search of aphides. The ant then taps the aphis gently with her antenne, and the aphis emits a drop of sweet fluid, which the ant drinks. Some- times the ants even build covered ways up to and over the aphides, which, moreover, they protect from the 4 26 » EFOOD—ENEMIES. attacks of other insects. Our English ants do not store up provision for the winter; indeed, their food is not of a nature which would admit of this. I have indeed observed that the small brown ant sometimes carries seeds of the violet into its nest, but for what purpose is not clear. Some of the southern ants, however, lay up stores of grain (see Chapter III.). Ants have many enemies. They themselves, and still more their young, are a favourite food of many animals. They are attacked also by numerous para- sites. Ifa nest of the brown ants is disturbed at any time during the summer, some small flies may probably be seen hovering over the nest, and every now and then making a dash at some particular ant. These flies belong to the genus Phora, and toa species hitherto unnamed, which Mr. Verrall has been good enough to describe for me (see Appendix). They lay their eggs on the ants, inside which the larve live. Other species of the genus are in the same way parasitic on bees. Ants are also sometimes attacked by mites. On one occasion I observed that one of my ants had a mite attached to the underside of its head. The mite, which maintained itself for more than three months in the same position, was almost as large as the head. The ant could not remove it herself. Being a queen, she did not come out of the nest, so that I could not do it for her, and none of her own companions thought of performing this kind office. In character the different species of anis differ very CHARACTER—INDUSTRY. 2? much from one another. F. fusca (Pl. I. fig. 3), the one which is pre-eminently the ‘slave’ ant, is, as might be expected, extremely timid; while the nearly alied F. cimerea has, on the contrary, a considerable amouut of individual audacity. F. rufa (Pl. Il. fig. 5), the horse ant, is, according to M. Forel, especially characterised by the want of individual initiative, and always moves in troops; he also regards the genus Formica as the most brilliant; though others excel it in other respects, as, for instance, in the sharpness of their senses. J’. pratensis worries its slain enemies; F. sanguinea (Pl. I. fig. 6) never does so. The slave-making ant (P. rufescens, Pl. I fig. 5) is, perhaps, the bravest of all. If a single indi- vidual finds herself surrounded by enemies, she never attempts to fly, as any other ant would, but transfixes her opponents one after another, springing right and left with great agility, till at length she succumbs, overpowered by numbers. M. scabrinodis is cowardly and thievish; during wars among the larger species they haunt the battle-fields and devour the dead. Tetramorium is said to be very greedy; Myrmecina very phlegmatic. In industry ants are not surpassed even by bees and wasps. They work all day, and in warm weather, if need be, even at night too. I once watched an ant from six in the morning, and she worked without intermission till a quarter to ten at night. I had put her to a saucer containing larvee, and in this time she 28 . GAMES, carried off no less than a hundred and eighty-seven to the nest. I had another ant, which I employed in my experiments, under continuous observation several days. When I started for London in the morning, and again when I went to bed at night, I used to put her ina small bottle, but the moment she was let out she began to work again. On one occasion I was away from home for a week. On my return I took her out of the bottle, placing her on a little heap of larve about three feet from the nest. Under these circum- stances I certainly did not expect her to return. How- ever, though she had thus been six days in confine- ment, the brave little creature immediately picked up a larva, carried it off to the nest, and after half an hour’s rest returned for another. Our countryman Gould noticed! certain * amuse- ments’ or ‘ sportive exercises,’ which he had observed among ants. Huber also mentions? scenes which he had witnessed on the surface of ant hills, and which, he says, ‘I dare not qualify with the title gymnastic, although they bear a close resemblance to scenes of that kind.’ The ants raised themselves on their hind legs, caressed one another with their antenne, engaged in mock combats, and almost seemed to be playing P hide and seek. Forel entirely confirms Huber’s state- ments, though he was at first incredulous. He says : 5— 1 An Account of English Ants, p. 103, 3 Nat Hist. of Ants, p. 197. * Loo. cit., p. 867. CLEANLINESS. 29 ‘ Malgré l'exactitude avec laquelle il décrit ce fait, Javais peine a y croire avant de V’avoir vu moi-méme, mais une fourmiliére pratensis m’en donna |’exemple & plusieurs reprises lorsque je l’approchai avec précaution. Des 8 (i.e. workers) se saisissaient par les pattes ou par les mandibules, se roulaient par terre, puis se retachaient, s’entrainaient les unes les autres dans les trous de leur déme pour en ressortir aussitét aprés, ete. Tout cela sans aucun acharnement, sans venin ; il était évident que c’était purement amical. Le moindre souffle de ma part mettait aussitét fin 4 ces jeux. J’avoue que ce fait. peut paraitre imaginaire 4 qui ne Va pas vu, quand on pense que l’attrait des sexes ne peut en étre cause.’ Bates, also, in the case of Eciton legionis, observed behaviour which looked to him ‘ like simple indulgence in idle amusement, the conclusion,’ he says, ‘ that the ants were engaged merely in play was irresistible.”! Lastly, I may observe that ants are very cleanly animals, and assist one another in this respect. I have often seen them licking one another. Those, moreover, which I painted for facility of recognition were gradue ally cleaned by their friends. ' Loo. o't., vol. ii. p. 868. CHAPTER If. ON THE FORMATION AND MAINTENANCE OF NESTS, AND ON THE DIVISION OF LABOUR. Iv is remarkable that notwithstanding the researches of so many excellent observers, and though ants’ nests swarm in every field and every wood, we did not know how their nests commence. Three principal modes have been suggested. After the marriage-flight the young queen may either— 1. Join her own or some other old nest ; 2. Associate herself with a certain number of workers, and with their assistance commence a new nest ; or 3. Found a new nest by herself, The question can of course only be settled by ob- servation, and the experiments made to determine it had hitherto been indecisive. Blanchard, indeed, in his work on the ‘ Metamor- phrses of Insects’ (I quote from Dr. Duncan’s transla- tion, p. 205), says :—* Huber observed a solitary female go down into a small under-ground hole, take off her own wings, and become, as it were, a worker; then she constructed a small nest, laid a few eggs, and brought ORIGIN OF AN ANTS’ NEST. 31 up the larve by acting as mother and nurse at the same time.’ This, however, is not a correct version of what Huber says. His words are :—‘ I enclosed several females in a vessel full of light humid earth, with which they constructed lodges, where they resided, some singly, othersincommon. They laid their eggs and took great care of them ; and notwithstanding the inconvenience of not being able to vary the temperature of their habi- tation, they reared some, which became larve of a tolerable size, but which soon perished from the effect of my own negligence.’ ! It will be observed that it was the eggs, not the larve, which, according to Huber, these isolated females reared. It is true that he attributes the early and uni- form death of the larve to his own negligence, but the fact remains that in none of his observations did an isolated female bring her offspring to maturity. Other entomologists, especially Forel and Ebrard, have repeated the same observations with similar results; and as yet in no single case had an isolated female been known to bring her young to maturity. Forel even thought himself justified in concluding, from his ob- servations and from those of Ebrard, that such a fact could not occur. Lepeletier de St. Fargeau? was of opinion that ants’ nests originate in the second mode indicated above, and * Natural History of Ants, Huber, p. 121. § Hist. Nat. des Ins. Hyménoptéres, vol. i. p. 148. 82 RELUCTANCE TO ADOPT A NEW QUEEN. it is, indeed, far from improbable that this may occur. No clear case has, however, yet been observed. M. de St. Fargeau himself observes! that ‘les particularités qui accompagnent la formation premiére d'une four- miliére sont encore incertaines et mériteraient d’étre observées avec soin.’ Under these circumstances I made the following experiments :— la. I took an old, fertile, queen from a nest of Lasius flavus, and put her to another nest of the same species, The workers became very excited and attacked her. b. I repeated the experiment, with the same result. c. Do. do. Inthis case the nest to which the queen was transferred was without a queen; still they would not receive her. dande. Do. do. do. I conclude, then, that, at any rate in the case. of L. flavus, the workers’ will not adopt an old queen from another nest. The following observation shows that, at any rate in some cases, isolated queen ants are capable of giving origin to a new community. On August 14, 1876, I isolated two pairs of Myr- mica ruginodis which I found flyingin my garden. I placed them with damp earth, food, and water, and they continued perfectly healthy through the winter, zs * Hist Nat, des Ins. Hyménoptéres, vol. i. p. 144 ORIGIN OF A NEST OF MYRMICA. 33 In April one of the males died, and the second in the middle of May. The first eggs were laid between April 12 and 23. They began to hatch the first week in June, and the first larva turned into a chrysalis on the 27th; asecond on the 30th; a third on July 1, when there were also seven larve and two eggs. On the 8th there was another egg. On July 8 a fourth larva had turned into a pupa. On July 11 I found: there were six eggs, and on the 14th about ten. On the 15th one of the pup began to turn brown, and the eggs were about 15 in number. On the 16th a second pupa began to turn brown. On the 2Ist a fifth larva had turned into a pupa, and there were about 20 eggs. On July 22 the first worker emerged, and a sixth larva had changed. On the 25th I observed the young worker carrying the larve about when I looked into the nest ; a second worker was coming out. On July 28 a third worker emerged, and a fourth on Aug 5. The eggs appeared to be less numerous, and some had probably been devoured. This experiment shows that the queens of Myrmica ruginodis have the instinct of bringing up larvee and the power of founding communities. The workers remained about six weeks in the egg,a month in the state of larvee, and twenty-five to twenty-seven days as pup. Since, however, cases are on record in which com munities are known to have existed for many years, it seems clear that fresh queens must be sometimes adopted I have indeed recorded several experiments 34 ADOPTION OF A QUEEN. in which fertile queens introduced into queeuless nesta were ruthlessly attacked, and subsequent experiments have always had the same result. Mr. Jenner Fust, however, suggested to me to introduce the queen into the nest, as is done with bees, in a wire cage, and leave her there for two or three days, so that the workers might, as it were, get accustomed toher. Accordingly I procured a queen of F. fusca and put her with some honey in a queenless nest, enclosed in a wire cage s0 that the ants could not get at her. After three days I let her out, but she was at once attacked. Perhaps I ought to have waited a few days longer. On the con- trary, Mr. McCook reports a case of the adoption of a fertile queen of Cremastogaster lineolata by a colony of the same species: '—‘The queen,’ he says, ‘was taken April 16, and on May 14 following was introduced to workers of a nest taken the same day. The queen was alone within an artificial glass formicary, and several workers were introduced. One of these soon found the queen, exhibited much excitement but no hostility, and immediately ran to her sister workers, all of whom were presently clustered upon the queen. As other workers were gradually introduced they joined their comrades, until the body of the queen (who is much larger than the workers) was nearly covered with them. They appeared to be holding on by their man- dibles to the delicate hairs upon the female’s body, and ‘ Proc. Acad Natural Sciences of Philadelphia, 1879. ‘Note on the Adoption of an Ant-Queen,’ by Mr McCook, p. 139. FERTILE WORKERS. ‘35 continually moved their antenne caressingly. This sort of attention continued until the queen, escorted by workers, disappeared in one of the galleries. She was entirely adopted, and thereafter was often seen moving freely, or attended by guards, about the nest, at times engaged in attending the larve and pupe which had been introduced with the workers of the strange colony. The workers were fresh from their own natural home, and the queen had been in an artificial home for a month.’ In no case, however, when I have put a queen into one of my nests has she been accepted. Possibly the reason for the difference may be that the ants on which I experimented had been long living in arepublic; for, I am informed, that if bees have been long without a queen it is impossible to induce them 'to accept another. Moreover, I have found that when I put a queen with a few ants from a strange nest they did not attack her, and by adding others gradually, I succeeded in securing the throne for her. , It is generally stated that among ants the queens only lay eggs. This, however, is not correct. Denny! and Lespés? have shown that the workers also are capable of producing eggs; but the latter as- serted that these eggs never come to maturity. Forel, however, has proved? that this is not the case, but 1 Ann. and Mag. Nat. Hist., 2nd ser., vol. £ § Ann. des Sci. Nat., 1863. ® Fourmis de la Suisse, p. 329 36 EGGS LAID BY FERTILE WORKERS that in some cases, at any rate, the eggs do produce young. Dewitz even maintains! that the workers habitually lay eggs, and explains the difference which mn this view exists between the workers of ants and those of bees, on the ground » 6.14 . a 6.15 4 - 6.16 bs a 6.17 a3 « 6.19 a . 6.20 - i 6.21 iF se 6.23 i - 6.25 as 6.27 Z 6.29 s e 6.30 . a EXPERIMENTS WITH MYRMICA AND LASIUS. 163 At 6.31 p.m. she returned and took another. Again 6.33 ‘i ” 6.35 “5 . 6.36 ss ‘ 6.37 3 ‘i 6.38 i 6.40 35 e 6.41 ‘5 6 6.45 3 3 6.47 - % 6.49 98 6.50 ‘5 - 6.51 " * 6.52 . é 6.53 3 Ss 6.55 ‘ ~ 6.56 ‘ a 6.57 i i 7 0 ” 9 7. 1 ” ” 7. 2 bP) ” 7. 6 ” ” After these 45 visits, she came no more till 8 P.M.; but when I returned at 10 p.m. I found all the pups gone. During the time she was watched, however, she brought no other ant to assist. I also made similar experiments with Myrmica ruginodis and Lasius niger, imprisoning (as before) all ants that came, except the marke ones, and with 164 EXPERIMENTS TO TEST similar results. The details will be feand in the Appendix, but need not be given in full here. I then tried the following experiment :— In figure 3, 4 is the ants’ nest, o the door of (pe nest. M is the section of a pole on which the whole apparatus is supported. B is a board 2 feet long; Cc, D, E, and F are slips of glass connected with the board B by narrow strips of paper G, H, 1 K is a movable strip of paper, 14 inch long, connecting the glass F with the strip H; and L is another movable strip of paper, as nearly as possible similar, connecting Hand I. On each of the slips of glass c and F I put several hundred larve of L. flavus. The object of the larve on Cc was to ascertain whether, under such circum- stances, other ants would find the larve acci- dentally ; and I may say at once that none fe # didso. I then put an ant (a), whom I had imprisoned overnight, to the larve on F. She took one, and, knowing her way, went straight home over the bridge K and down the strip H. Now it is obvious that by always causing the marked ant (4) to cross the bridge K on a particular piece of paper, and if at other times the papers K and L were reversed, I should be able to ascertain whether other ants who came to the larve had had the direction and position explained to them ; o1 whether, having only Fig. 3. POWERS OF COMMUNICATION. 165 been informed by a of the existence of the larve, they found their way to them by tracking 4’s footsteps. If the fermer, they would in any case pass over the bridge kK by whichever strip of paper it was constituted. Or the other hand, if they found the larve by tracking then as the piece of paper by which 4 passed was transferred to L, it would mislead them and carry them away from the larve to 1. In every case, then, I trans- posed the two papers forming the little bridges as soon as the ant a had crossed over K and L. I put her (November 7, 1875) to the larve on F at 6.15 a.m. After examining them carefully, she re- turned to the nest at 6.34. No other ants were out; but she at once reappeared with four friends and reached the larve at 6.38. None of her friends, how- ever, crossed the bridge; they went on to D, wandered about, and returned home. a returned to the larvee at 6.47, this time with one friend, who also went on to D and returned without finding the larve. 7. 0. Ant a to larvae. 7. 8 5 Anant at ae are L tol. 7.17 a with a friend, who at 7.21 i with two friends, 226 " one of whom | aat e 7.32 ‘3 the other at 7.35 * with a friend who 7.39, [rs on to D, “| 7.Al ” then at. ..... 166 EXPERIMENTS TO TEST 7.46 Ant 4 to larve. An ant at 7.42 ee 7.55 is 5 7.47 3 83 x ~— 8 8. 8 ” ” 7.54 ” 8.19 ~ SR? 8.24 3 ‘s 9.10 found the larvee. 8.39 ” 0 9.30 went over L to I. 8.50 4 912, 9.22 9.40 45 9.47 > 9.55 4 10.35 4g At 10.35 I imprisoned her till 12.30, when I put her again to the larvee. 12.48 back to larvee. 12.55 5 An ant at 12.58 went over L tol. 1. 0 ” be 1. 1 bb) > 1.15 ” ” 1.10 ” ” 1.20 3 ss 1.13 59 3 After this she did not come any more. During the time she made, therefore, 25 visits to the larve; 21 other ants came a distance of nearly 4 feet from the nest and up to the point of junction within 2 inches of POWERS OF COMMUNICATION. 16? the larve ; but only one passed over the little bridge to the larva, while 15 went over the bridge L tol On repeating this experiment with another marked ant, she herself made 40 journeys, during which 19 other ants found their way to the point of junction. Only 2 went over the little bridge to the larvae, 8 went over L to I, and the remainder on to D. In another similar experiment the marked ant made 16 journeys; and during the same time 13 other ants came to the point of junction. Of these 13, 6 went on to D, 7 crossed over L to I, and not one found the larve. Thus altogether, out of 92 ants, 30 went on to p, 51 crossed over in the wrong direction to 1, and only 11 found their way to the larva. From January 2 to January 24 (1875) I made a series of similar observations; and during this time 56 ants came in all. Of these, 20 went straight on to D, 26 across the paper to 1, and only Fig. 4. 10 to the larve. This, I think, gives strong reason to conclude that, under such circumstances. ants track one another by scent. I then slightly altered the arrange- B ment of the papers as shown in the accompanying diagram (fig. 4). A, as before, is the nest, o being the door. B is the board; h is a glass on which are placed the larve; m is a similar glass, but empty 3 n a strip of paper: to the end of m are pinned two 168 EXPERIMENTS TO TEST other strips f and g, in such a manner that they can be freely turned round, so that each can be turned at will either to h or m. Under ordinary circumstances the paper f, as in the figure, was turned to the larvee; but whenever any ant, excepting the marked one, came, I turned the papers, so that f led to mandgtoh. The result was striking, and I give the observation in full in the Appendix. In all, 17 ants came, every one of. whom took the wrong turn and went to m. Although the observations above recorded seem to Fig. 5. me almost conclusive, still I varied the experiments once more (see fig. 5), making the connexion between the board B and the glass containing the larve by three separate but similar strips of paper, d, e, and f, as shown in the figure. Whenever, however, a strange ant came, [ took up the strip f m and rubbed my finger over it two or three times so as to remove any scent, and then re- placed it. As soon as the stranger had reached the paper e, I took up the strip d, and placed it so as to connect ¢ with the empty glass m. ThusI escaped the necessity of changing the paper f, and yet had a scented brilge between e and m. The details, as before, are given in the Appendix. In this experiment the bridge over which the marked ant passed to the larve was left in its place, the scent, however, being removed or obscured by the POWERS OF COMMUNICATION. 169 friction of my finger ; on the other hand, the bridge (d) had retained the scent, but was so placed as to lead away from the larvee; and it will be seen that, under these circumstances, out of 41 ants which found their way towards the larve as far as e, 14 only passed over the bridge f to the larve, while 27 went over the bridge d to the empty glass m. Taking these observations as a whole, 150 ants came to the point e, of which 21 only went on to the larvee, while 95 went away to the empty glass. These experiments, therefore, seem to show that when an ant has discovered a store of food and others flock to it, they are guided in some cases by sight, while in others they track one another by scent. I then varied the experiment as follows :—I put an ant (L. niger) to some larve as usual, and when she knew her way, I allowed her to go home on her own legs; but as soon as she emerged from the nest, if she had any friends with her, I took her up on a bit of paper and carried her to the larvee. Under these circumstances very few ants indeed found their way tothem. Thus, on June 23, 1876, at 5.30, an ant which had been previously under observation was put to some larve. She took one and returned as usual to the nest. At 5.34 she came out with no less than 10 friends, and was then transferred to the larve. The others wandered about a little, but by degrees returned to the nest, not one of them finding their way to the larve. The first ant picked up a larva, returned, and again came out 13 170 EXPERIMENTS TO TEST of the nest at 5.39 with 8 friends, when exactly the same thing happened. She again came out with companions at the undermentioned times :— Number of Number of Hour. Friends, Hour. Friends. 5.44 4 6.44 —_— 5.47 4 6.46 3 5.49 _— 6.49 2 5.52 _— 6.56 —_— 5.54 5 6.59 —_— 5.57 2 7. 2 2 5.59 2 7. 4 _— 6. 1 5 7. 6 3 6. 4 1 7.8 3 6. 7 — 7.10 5 6.11 3 7.13 _— 6.14 4 | 7.17 3 6.17 6 7.19 7 6.20 —_— 7.21 5 6.23 5 7.24 —_ 6.25 6 7.26 3 6.29 8 7.29 1 6.32 2 7.31 2 6.35 — 7.35 — 6.42 4 Thus during these two hours more than 120 anta came out of the nest in company with the one under observation. She knew her way perfectly; and it is POWERS OF COMMUNICATION. 171 elear that if she had been left alone, all, o1 at least most of, these ants would have accompanied her to the store of larve. Three of them were accidentally allowed to do so; but of the remainder, only 5 found their way to the larve; all the others, after wandering about a while, returned hopelessly to the nest. One of the ants which I employed in my experi- ments was under observation several days. I was, however, away from home most of the day, and when I left in the morning and went to bed at night I put her in a bottle ; but the moment she was let out she began to work again. On one occasion I was away for a week, and on my return I let her out of the bottle, placing her on a little heap of larve about 3 feet from the nest. Under these circumstances I certainly did not expect her to return. However, though she had thus been six days in confinement, the brave little creature immediately picked up a larva, carried it off to the nest, and, after half an hour’s rest, returned for another. I conclude, then, that when large numbers of ants come to food they follow one another, being also to a certain extent guided by scent. The fact, therefore, does not imply any considerable power of intercom~ munication. There are, moreover, some other circum- stances which seem to show that their powers in this respect are but limited. For instance, I have already mentioned that if a colony of Polyergus changes the situation of its nest, the mistresses are all carried to the new one by the slaves. Again, if a number of F. 172 EVIDENCE OF COMMUNICATION, fusca are put in a box, and in one corner a dark place of retreat is provided for them with some earth, one soon finds her way toit. She then comes out again, and going up to one of the others, takes her by the jaws. The second ant then rolls herself into a heap, and is carried off to the place of shelter. They then both repeat the same manceuvre with other ants, and so on until all their companions are collected together. Now it seems to me difficult to imagine that so slow a course would be adopted if they possessed any considerable power of descriptive communication, On the other hand, there can, I think, be no doubt that they do possess some power of the kind. This seems to me clearly shown by the following observations. In order, if possible, to determine whether the ants in question were brought to the larvee, or whether they came casually, I tried (1875) the following experiments: I took three tapes, each about 2 feet 6 inches long, and arranged them parallel to one another and about 6 inches apart. One end of each I attached to one of my nests (L. niger), and at the other end I placed a small glass. In the glass at the end of one tape I placed a considerable number (300 to 600) of larvae. In the second I put two or three larve only; in the third none at all, The object of the last was to see whether ‘many ants would come to the glasses under such cir- cumstances by mere accident; and I may at once say that but few did so. I then took two ants and EVIDENCE OF COMMUNICATION. 173 placed one of them to the glass with many larvae, the other to that with two or three. Each of them took a larva and carried it to the nest, returning for another, and soon. After each journey I put another larva in the glass with only two or three larve, to replace that which had been removed. Now, if other ants came under the above circumstances as a mere matter of accident, or accompanying one another by chance, or if they simply saw the larve which were brought and consequently concluded that they might themselves also find larve in the same place, then the numbers going to the two glasses ought to be approximately equal. In each case the number of journeys made by the ants would be nearly the same ; consequently, if it was a matter of scent, the two glasses would be in the same position. It would be impossible for an ant, seeing another in the act of bringing a larva, to judge for itself whether there were few or many larve left behind. On the other hand, if the friends were brought, then it would be curious to see whether more were brought to the glass with many larve, than to that which only contained two or three. I should also mention that, excepting, of course, the marked spec?- mens, every ant which came to the larve was im- prisoned until the end of the experiment. I give the details in the Appendix. The results of the above experiments are shown at a glance in the following Table :— 174 EVIDENCE OF COMMUNICATION. Tabular View of Experiments on Power of Communication Glass with many larvae Glass with one or two larves Obser- vations | Time | No.of | No.of Time | No.of | No.of occupied | journeys | friends occupied | journeys | friends hours hours 1 1 7 11 2 —_— —_— —_— 1 6 0 3 _ —_— _ 2 13 8 4 -— —_ _ 3 24 6 5 3 38 22 1 10 3 6 23 32 19 7 1 5 16 8 13 11 ZL 3 23 2 9 — _— —_ 14 7 3 10 1 15 13 2 21 1 11 2 32 20 1 11 1 12 5 26 10 13 = ae acs 5 19 1 14 = = — 8 20 4 16 24 41 3 2 5 0 16 1 10 16 34 10 2 17 44 53 2 45 40 10 18 ie _ — 2 20 1 19 1 El 12 20 _ _ _ 1 6 0 21 1k 20 ig 4} 74 27 22 —_ _— _ 1g 25 4 23 4} 7 7 24 _ — _ 2 35 4 25 2 34 3 26 1} 35 21 2 18 0 27 2 37 9 14 15 0 28 4 9 10 2 14 0 29 2 37 5 13 25 3 30 Wu 9 10 2 14 0 3L 2 37 5 1} 25 3 32° 2 24 7 1 7 0 33 33 43 ay 33 26 1 34 1 27 28 1 18 12 35 1 14 2 1 16 9 52 678 304 59} 545 104 It must be admitted that this mode of observing EVIDENCE OF COMMUNICATLIUN. 173 is calculated to increase the number of friends brought by the ants to the glass with only 2 or 3 larve, for several reasons, but especially because in many cases an ant which had for some time had access to a glasa with many larve was suddenly deprived of it, and it might well be that some time elapsed before the change was discovered. Some stray ants would, no doubt, in any case have found the larve; and we may probably allow for ahout 25 under this head. Again, some would, no doubt, casually accompany their friends ; if we allow 25 also in this respect, we must deduct 50 from each side, and we shall have 254 against 54. Nevertheless, even without any allowances, the results seem to me very definite. Some of the individual cases, especially perhaps experiments 9, 10, 20, 21, and 22 (see Appendix), are very striking ; and, taken as a whoie, during 52 hours, the ants which had access to a glass containing numerous larve brought 304 friends ; while during 59 hours those which were visiting a glass with only 2 or 3 larve brought only 104 to their assistance. One case of apparent communication struck me very much. I had had an ant (LZ. niger) under obser- vation one day, during which she was occupied in carrying off larve to her nest. At night I imprisoned her in a small bottle; in the morning I let her out at 6.15, when she immediately resumed her occupation. Having to go to London, I imprisoned her again at 9 o'clock. When I returned at 4.40, I put her again 176 EVIDENCE OF COMMUNICATION. to the larve. She examined them carefully, but went home without taking one. At this time no other ants were out of the nest. In less than a minute she came out again with 8 friends, and the little troop made straight for the heap of larve. When they had gone two-thirds of the way, I again imprisoned the marked ants; the others hesitated a few moments, and then, with curious quickness, returned home. At 5.15 I put her again to the larve. She again went home without a larva, but, after only a few seconds’ stay in the nest, came out with no less than 13 friends. They all went towards the larve; but when they got about two-thirds of the way, although the marked ant had on the previous day passed over the ground about 150 times, and though she had just gone straight from the larve to the nest, she seemed to have forgotten her way and wandered; and after she had wandered about for half an hour, J put her to the larve. Now in this case the 21 ants must have been brought out by my marked one; for they came exactly with her, and there were no other ants out. Moreover, it would seem that they must have been told, because (which is very curious in itself) she did not in either case bring a larva, and consequently it cannot have been the mere sight of a larva which induced them to follow her. I repeated an experiment similar to this more than once. For instance, one rather cold day, when but few ants were out, I selected a specimen of Atta ‘testaceo EXPERIMENT WITH AN ATTA 177 pilosa, belonging to a nest which I had brought back with me from Algeria. She was out hunting about six feet from home, and I placed before her a large dead bluebottle fly, which she at once began to drag to the nest. I then pinned the fly to a piece of cork, in a small box, so that no ant could see the fly until she had climbed up the side of the box. The ant struggled, of course in vain, to move the fly. She pulled first in one direction and then in another, but, finding her efforts fruitless, she at length started off back to the nest empty-handed. At this time there were no ants coming out of the nest. Probably there were some few others out hunting, but for at least a quarter of an hour no ant had left the nest. My ant entered the nest, but did not remain there; in less than a minute she emerged accompanied by 7 friends. I never saw so many come out of that nest together before. In her excitement the first ant soon distanced her companions, who took the matter with much more sang-froid, and had all the appearance of having come out reluctantly, or as if they had been asleep and were only half awake. The first ant ran on ahead, going straight to the fly. The others followed slowly and with many meanderings; so slowly, indeed, that for twenty minutes the first ant was alone at the fly, trying in every way to move it. Finding this still impossible, she again returned to the nest, not chancing to meet any of her friends by the way. Again she emerged in less than a minute with 8 friends, and 178 EXPERIMENT WITH AN ATTA. hurried on to the fly. They were even less energetic than the first party; and when they found they had lost sight of their guide, they one and all returned to the nest. In the meantime several of the first detach- ment had found the fly, and one of them succeeded in detaching a leg, with which she returned in triumph to the nest, coming out again directly with 4 or 5 companions. These latter, with one exception, soon gave up the chase and returned to the nest. I do not think so much of this last case, because as the ant carried in a substantial piece of booty in the shape of the fly’s leg, it is not surprising that her friends should some of them accompany her on her return; but surely the other two cases indicate a distinct power of communication. Lest, however, it should be supposed that the result was accidental, I determined to try it again. Accord. ingly on the following day I put avother large dead fly before an ant belonging to the saine nest, pinning it to a piece of cork as before. After trying in vain for ten minutes to move the fly, my ant started off home. At that time I could only see two other ants of that species outside the nest. Yet in a few seconds, con- siderably less than a minute, she emerged with no less than 12 friends. As in the previous case, she ran on ahead, anc they followed very slowly and by no means directly, taking, in fact, nearly half an hour to reach the fly. The first ant, after vainly labouring for about a quarter of an hour to move the fly, started off EXPERIMENT WITH AN ATTA. 179 again to the nest. Meeting one of her friends on the way she conversed with her a little, then continued © towards the nest, but, after going about a foot, changed her mind, and returned with her friend to the fly. After some minutes, during which two or three other ants came up, one of them detached a leg, which she carried off to the nest, coming out again almost immedi- ately with six friends, one of whom, curiously enough, seemed to lead the way, tracing it, I presume, by scent. T then removed the pin, and they carried off the fly in triumph. Again, on June 15, 1878, another ant belonging to the same nest had found a dead spider, about the same distance from the nest. I pinned down the spider as before. The ant did all in her power to move it; but after trying for twelve minutes, she went off to the nest. Although for a quarter of an hour no other ant had left the nest, yet in a few seconds she came out again with 10 companions. As in the preceding case, they followed very leisurely. She ran on ahead and worked at the spider for ten minutes; when, as none of her friends had arrived to her assistance, though they were wan- dering about, evidently in search of something, she started back home again. In three quarters of a minute after entering the nest she reappeared, this time with 15 friends, who came on somewhat more rapidly than the preceaing batch, though still but slowly. By degrees, however, they all came up, and after most persevering efforts carried off the spider 180 EXPERIMENT WITH PHEIDOLE. piecemeal. On July 7,1 tried the same experiment with a soldier of Pheidole megacephala. She pulled at the fly for no less than fifty minutes, after which she went to the nest and brought five friends exactly as the Atta had done. . In the same way, one afternoon at 6.20 I presented a slave of Polyergus with a dead fly pinned down. The result was quite different. My ant pulled at the fly for twenty-five minutes, when, as in the previous cases, she returned to the nest. There she remained four or five minutes, and then came out again alone, returned to the fly, and again tried to carry it off. After working fruitlessly for between twenty and twenty- five minutes, she again went back to the nest, staying there four or five minutes, and then returning by her- self to the fly once more. I then went away for an hour, but on my return found her still tugging at the fly by herself. One hour later again I looked, with the same result. Shortly afterwards another ant wandering about found the fly, but obviously, as it seemed to me, by accident. At 3 o’clock on a subsequent day I again put a dead fly pinned on to a bit of cork before a Formica fusca, which was out hunting. She tried in vain to carry it off, ran round and round, tugged in every direction, and at length at ten minutes to four she returned to the nest: very soon after she reappeared preceded by one and followed by two friends; these, however, failed to dis- cover the fly, and after wandering about a little returned EXPERIMENT WITH FORMICA. 181 to the nest. She then set again to work alone, and in about forty minutes succeeded in cutting off the head of the fly, which she at once carried into the nest. In alittle while she came out again, this time accompanied by five friends, all of whom found their way to the fly ; one of these, having cut off the abdomen of the fly, took it into the nest; leaving three of her companions to bring in the remainder of their prey. These experiments certainly seem to indicate the possession by ants of something approaching to lan- guage. It is impossible to doubt that the friends were brought out by the first ant; and as she returned empty-handed to the nest, the others cannot have been induced to follow her merely by observing her proceed- ings. In face of such facts as these, it is impossible not to ask ourselves how far are ants mere exquisite automatons ; how far are they conscious beings? When we see an ant-hill, tenanted by thousands of industrious inhabitants, excavating chambers, forming tunnels, making roads, guarding their home, gathering food, feeding the young, tending their domestic animals, —each one fulfilling its duties industriously, and without confusion,—it is difficult altogether to deny to them the gift of reason; and the preceding observa- tions tend to confirm the opinion that their mental powers differ from those of men, not so much in kind ne in degree. CHAPTER VIII. ON THE SENSES OF ANTS. The Sense of Vision. In is, I think, generally assumed not only that the world really exists as we see it, but that it appears to other animals pretty much as it does to us. A little con- sideration, however, is sufficient to show that this is very far from being certain, or even probable. In the case of insects, moreover, the mode of vision is still an enigma. They have, at least many of them have, a large compound eye on each side; and ocelli, generally three in number, situated on the summit of the head. The compound eyes consist of a number of facets, each situated at the summit of a tube, to the base of which runs a fibre of the optic nerve. The structure of the ocellus and that of the com- pound eye are essentially different, and it does not seem possible that either the ocellus should be derived from the compound eye, or the compound eye from the ocel- lus. On the contrary, both seem to point back tc a less developed ancestral type. Starting from such an origin, an increase of the separate elements and an im- provement of the lens would lead to the ocellus, while TWO KINDS OF EYES. 183 an increase of the number of eyes would bring us to the compound eye. On the other hand, it must be admitted that there are reasons for considering the different kinds of eyes to be of perfectly distinct origin. The eye of Limulus, according to Grenacher, is formed on a plan quite unlike that of other Crustacea. Again, the develop- ment of the eye in Musca, to judge from Weismann’s observations, is very dissimiliar from that of other insects. The varied position of the eye in different groups, as, for instance, in Pecten, Spondylus, Euphausia, Onchidiwm, &c., point to the same con- clusion. It seems clear that the image produced by the ocelli must be altogether different from the picture given by the compound eyes; and we may therefore reasonably -onclude that the two organs have distinct functions. It used formerly to be supposed that the compound eyes were intended for distant, the ocelli for near vision. Claparéde, however, has maintained the opposite theory, while Mr. Lowne regards the ocelli as incapable of producing ‘anything worthy the name of an image,’ and suspects that their function ‘is the perception of the intensity in the direction of light, rather than vision.’ The ocelli, or simple eyes, probably see in the same manner as ours do. That is to say, the lens throws an | image on the back of the eye, which we call the retina. In that case they would see everything really reversed, 184 HOW INSECTS SEE. as we do; though long practice has given us the right impression. The simple eye of insects thus resembles ours in this respect. . As regards the mode of vision of the compound eyes, there are two distinct theories. According to one— the mosaic theory of Miiller—each facet takes in only a small portion of the field; while according to the other, each facet acts as a separate eye. This latter view has been maintained by many high authorities, but it is difficult to understand how so many images could be combined into one picture. Some insects have more than 20,000 facets on each side of their head. No ants, indeed, have so many, but in some—as, for instance, in the males of Formica pratensis — there are not less than 1,000. The theory, moreover, presents some great anatomical difficulties. Thus, in certain cases there is no lens, and conse- quently there can be no image ; in some it would seem that the image would be formed completely behind the eye, while in others again it would be in front of the receptive surface. Another difficulty is that any true projection of an image wuld in certain species be pre- cluded by the presence of impenetrable pigment, which only leaves a minute central passage for the light-rays. Again, it is urged that even the sharpest image would _ be useless, from the absence of a suitably receptive surface ; since the structure of the receptive surface corresponding to each facet seems to preclude it from receiving more than a single impression. THE MOSAIC THEORY. 185 The prevailing opinion of entomologists now is that each facet receives the impression of one pencil of rays ; so that, in fact, the image formed in a compound eye is a sort of mosaic. On the other hand, this theory itself presents great difficulties. Those ants which have very few facets must have an extremely imperfect vision. Again, while the image produced on the retina of the ocellus must of course be reversed as in our own eyes} in the compound eyes, on the contrary, the vision would, on this theory, be direct. That the same animal should see some things directly, and others reversed ; and yet obtain definite conceptions of the outer world, would certainly be very remarkable. In fact, these, so far fortunate, insects realise the epigram of Plato— Thou lookest on the stars, my love, Ab, would that I could be Yon starry skies, with thousand eyes That 1 might look on thee! But if the male of F. pratensis sees 1,000 queens at once, when only one is really present, this would seem to be a bewildering privilege, and the prevailing opinion among entomologists is, as already mentioned, that each facet only takes in a portion of the object. But while it is difficult to understand how ants see, it is clear that they do see From the observations of Sprengel there could of 14 186 LIMITS. OF VISION. course be little, if any, doubt, that bees are capable of distinguishing colours; and I have proved experi- mentally that this is the case. Under these circum- stances, I have been naturally anxious to ascertain, if possible, whether the same holds good with ants. I have, however, found more difficulty in doing so because, as shown in the observations just recorded, ants find their food so much more by smell than by sight. This being so, I could not apply to ants those tests which had been used in the case of bees. At length, however, it occurred to me that I might utilize the dislike which ants, when in their nests, have to light. Of course they have no such feeling when they are out in search of food; but if light is let in upon their nests, they at once hurry about in search of the darkest corners, and there they all congregate. If, for instance, I uncovered one of my nests and then placed an opaque substance over one portion, the ants invariably collected in the shaded part. I procured, therefore, four similar strips of glass, coloured respectively green, yellow, red, and blue, or, rather, violet. The yellow was rather paler in shade, and that glass consequently rather more transparent than the green, which, again, was rather more trans- parent than the red or violet. I also procured some coloured solutions. Prof. Dewar was kind enough to test my glasses and solutions with reference to their power of trans- POWER OF DISTINGUISHING COLOURS. 187 mitting colour. Taking the wave-length of the ex- treme visible red as 760 and that of the extreme violet as 397, we have 760 to 647 give red. 647 ,, 585 ,, orange. 585 ,, 575 ,, yellow. 575 ,, 497 ,, green. 497 ,, 455 ,, blue. 445 ,, 397 ,, violet. The result of his examination of my glasses and solutions was as follows :— The light-yellow glass cut off the high end down to wave-length 442. The dark-yellow glass cut off the high end down to wave-length 493. The green glass cut off the high end down to wave- length 465, and also the red to 616. The red glass cut off the high end down to wave- length 582. The violet glass cut off the orange and yellow from wave-length 684 to 583, and a band between wave-lengths 543 and 516. The purple glass cut off the high end down to wave-length 528. The solution of chromate of potash cut off the high end to 507. The saffron cut off the high end to about 473, The blue fluid cut off the low end to 516. The red fluid cut off the high end to 596, :88 EXPERIMENTS WITH COLOURED GLASSES. I then (July 15, 1876) laid the strips of g'ass on one of my nests of Formica fusca, containing about 170 ants. These ants, as I knew by many previous observations, seek darkness, at least when in the nest, and would collect in the darkest part. I then, after counting the ants under each strip, moved the glasses, at intervals of about half an hour, so that each should by turns cover the same portion of the nest. The results were as follows—the numbers indicating the approximate numbers of ants under each glass (there were sometimes a few not under any of the strips of glass) :— 1. Green. Yellow. Red. Violet. 50 40 80 0 2. Violet. Green. Yellow. Red. 0 20 40 100 3. Red. Violet. Green. Yellow. 60 0 50 50 4, Yellow. Red. Violet. Green. 50 70 1 40 5. Green. Yellow. Red. Violet. 30 30 100 0 6. Violet. Green. Yellow. Red. 0 14 5 140 7. Red. Violet. Green. Yellow 50 0 40 70 8. Yellow. Red. Violet. Green. 40 50 1 70 EXPERIMENTS WITH COLOURED GLASSES. 189 9. Green. Yellow. Red. Violet. 60 85 65 0 10. Violet. Green. Yellow. Red. 1 50 40 70 ll. Red. Violet. Green. “Yellow. 50 2 50 60 12. Yellow. Red. Violet. Green. 85 55 0 70 Adding these numbers together, there were, in the twelve observations, under the red 890, under the green 544, under the yellow 495, and under the violet only 5. The difference between the red and the green is very striking, and would doubtless have been more so, but for the fact that when the colours were trans- posed the ants which had collected under the red sometimes remained quiet, as, for instance, in cases 7 and 8. Again, the difference between the green and yellow would have been still more marked but for the fact that the yellow always occupied the position last held by the red, while, on the other hand, the green had some advantage in coming next the violet. In considering the difference between the yellow and green, we must remember also that the green was decidedly more opaque than the yellow. The case of the violet glass is more marked and more interesting. To our eyes the violet was as opaque as the red, more so than the green, and much more so than the yellow. Yet, as the numbers show, the ants 190 EXPERIMENTS WITH COLOURED GLASSES. had scarcely any tendency to congregate under it There were nearly as many under the same area of the uncovered portion of the nest as under that shaded >y the violet glass. ‘i Lasius flavus also showed a marked avoidance of the violet glass. I then experimented in the same way with a nest of Formica fusca, in which there were some pupe, which were generally collected in a single heap. I used glasses coloured dark yellow, dark green, light yellow, light green, red, violet, and dark purple. The colours were always in the preceding order, but, as before, their place over the nest was changed after every observation. To our eyes the purple was almost black, the violet and dark green very dark and quite opaque ; the pupe could be dimly seen through the red, rather more clearly through the dark yellow and light green, while the light yellow were almost transparent. There were about 50 pup, and the light was the ordinary diffused daylight of summer. These observations showed a marked preference for the greens and yellows. The pupe were 63 times under dark green, 3 under dark yellow, 33 under red, and once each under light yellow and light green, the violet and purple being altogether neglected. ] now tried the same ants under the same colours, but in the sun; and placed a shallow dish containing some 10 per cent. solution of alum sometimes over EXPERIMENTS WITH COLOURED GLASSES, 19} +he yellow, sometimes over the red. I also put four thicknesses of violet glass, so that it looked almost black. Undcr these circumstances, the pups were placed under the red 7 times, dark yellow 5, once they were half under each, but never under the violet, purple, light yellow, dark or light green. The following day I placed over the same nest, in the sun, dark green glass, dark red, and dark yellow. Tn nine observations the pup were carried three times under the red and nine times under the yellow. I then tried a similar series of experiments with Lasius niger, using a nest in which were about 40 pupe, which were generally collected in a single heap all together. As before, the glasses were moved in regular order after each experiment ; and I arranged them so that the violet followed the red. As far, therefore, as position was concerned, this gave violet rather the best place. The glasses used were dark violet, dark red, dark green, and yellow, the yellow being distinctly the most transparent to our eyes. Experiment Experiment 1. Pupe under yellow. 8. Pups under green. 2. 2” ” 9. ” red. 3. ” ” 10. ” yellow. 4. ” ” 11. ”° red. 5. ” ” 12. ” yellow, 6. 5 _ 13, ‘ a a. a green. 14, fn red, 192 EXPERIMENTS WITH COLOURED GLASSES. Experiment Experiment 15. Pupz under green. 24. Pupe under red. 16. 2 » 25. ‘3 yellow. 17. 9 yellow. | 26. » red. ! 8 = 29 29 2 7. ” ”° 19 7 red, 28. 7 ” 20. 99 29 2 9 ” ” 21. 6 yellow. | 30. * yellow. 22. ” ” 31. °° red. 23. ” ” 32. 3 green. I now put two extra thicknesses of giass over the red and green. 33. Pupz under red. 37. Pup under red. 34. “5 yellow. 38. PA = 35. 4 red. 39. 0 yellow. 36. <9 yellow. 40. 35 red. The result is very striking, and in accordance with the observations on Formica fusca. In 40 experi- ments the pups were carried under the yellow 19 times, under the red 16 times, and under the green 5 times only, while the violet was quite neglected. After the first twenty observations, however, I removed it. I then tried a nest of Cremastogaster scutellaris with violet glass, purple glass, and red, yellow, and green solutions, formed respectively with fuchsine, bichromate of potash, and chloride of copper. The purple looked almost black, the violet very dark; the EXPERIMENTS WITH COLOURED GLASSES. 193 red and green, on the contrary, very transparent, and the yellow even more so. The yellow was not darker than a tincture of saffron. The latter indeed, to my eye, scarcely seemed to render the insects under them at all less apparent ; while under the violet and purple I could not trace them at all. I altered the relative positions as before. The nest contained about 50 larvee and pup. I made thirteen trials, and in every case the larve and pup were brought under the yellow or the green —never once under any of the other colours. Again, over a nest of Formica fusca containing about 20 pupz I placed violet glass, purple glass, a weak solution of fuchsine (carmine), the same of chloride of copper (green), and of bichromate of potash (yellow, not darker than saffron). I made eleven trials, and again, in every case the pup were brought under the yellow or the green. I then tried a nest of Lasius flavus with the purple glass, violet glass, very weak bichromate of potash, and chloride of copper as before. Witk this species, again, the results were the same as in the previous cases. In all these experiments, therefore, the violet and purple light affected the ants much more strongly than the yellow and green. It is curious that the coloured glasses appear to act on the ants (speaking roughly) as they would, or, 194 DISLIKE OF VIOLET. I should rather say, inversely as they would, on a photographic plate. It might even be alleged that the avoidance of the violet glass by the ants was due to their preferring rays transmitted by the other glasses. From the habits of these insects such an explanation would be very improbable. If, however, the preference for the other coloured glasses to the violet was due to the trans- mission and not to the absorption of rays—that is to say, if the ants went under the green rather than the violet because the green transmitted rays which were agreeable to the ants, and which the violet glass, on the contrary, stopped—then, if the violet was placed over the other colours, they would become as distasteful to the ants as the violet itself. On the contrary, how- ever, whether the violet glass was placed over the others or not, the ants equally readily took shelter under them. Obviously, therefore, the ants avoid the violet glass because they dislike the rays which it transmits. But though the ants so markedly avoided the violet glass, still, as might be expected, the violet glass cer- tainly had some effect, because if it were put over the nest alone, the ants preferred being under it to being under the plain glass only. I then compared the violet glass with a solution of ammorio-sulphate of copper, which is very similar in colour, though perhaps a little more violet, and arranged the depth of the fluid so as to make it as nearly as poss sibie of the same depth of colour as the glass, EXPERIMENTS WITH COLOURED SOLUTIONS. 194 Approx. number of Exp. 1, Exp. 2 Exp.3. Exp.4. Exp. 6. Exp. 6. under the Glass... 0 0 0 2 0 2 Solution... 40 80 100 80 50 70 Exp.7, Exp.& Exp.9. Exp.10. Total Glass... 0 2 3 0 wee 9 Solution... 60 40 90 100 see 710 In another experiment with Lasius niger I used the dark yellow glass, dark violet glass, and a violet solution of 5 per cent. ammonio-sulphate of copper, diluted so as to be, to my eye, of exactly the same tint as the violet glass; in 8 observations the pupz were three times under the violet solution, and 5 times under the yellow glass. I then removed the yellow glass, and in 10 more observations the pupe were always brought under the solution. It is interesting that the glass and the solution should affect the ants so differently, because to my eye the two were almost identical in colour. The glass, however, was more transparent than the solu- tion. To see whether there would be the same difference between red glass and red solution as between violet glass and violet solution, I then (Aug. 21) put over a nest of Formica fusca a red glass and a solution of carmine, as nearly as I could make it of the same tint. In 10 experiments, however, the ants were, generally speaking, some under the solution and some under the glass, in, moreover, as nearly as possible equal numbers. August 20.—Over a nest of Formica fusca cons 196 EXPERIMENTS WITH COLOURED SOLUTIONS. taining 20 pupe, I placed a saturated solution of bichromate of potash, a deep solution of carmine, which let through scarcely any but the red rays, and a white porcelain plate. bs. aE Under the bichr. of potash were 0 pup, carmine 18, porcelain 2 2 » ” 0 ” ” 6 ” 14 3. yw ” 6 ” ” 3 » il 4 ” » 0 ” ” 5 ” 18 5. ” ” 6 ” ” 4 ” 10 6. » ” 0 ” ” 19 ” 1 T. ” » 0 ” ” 0 ” 20 8 Ad ” 4 » a 16 ” 1 9 ” ” 2 ” ” 4 ” 14 10. ” » 0 » ” 4 4, 16 il ” ” 0s ” 3 ” 17 Total 18 81 124 I then put over another nest of Formica fusca four layers of red glass (which, when examined with the spectroscope, let through red light only), four layers of green glass (which, examined in the same way, transmitted nothing but a very little green), anda porcelain plate. Under these circumstances the ants showed no marked preference, but appeared to feel equally protected, whether they were under the red glass, the green glass, or the porcelain, Thus, though it appears from other experiments that ants are affected by red light, still the quantity that passes through dark red glass does not seem greatly to disturb them. I tested this again by placing over a nest containing a queen and about 10 pupe a piece of EXPERIMENTS ON A QUEEN ANT. 197 opaque porcelain, one of violet, and one of red glass, al of the same size. The result is shown below. Obs upze were taken under 1, Queen went under red glass 5 Ae der red glass { porcelair 2. me porcelain 0 ¥ 7 ” 3. ay red glass 0 “s 7 ” 4. » ” 6 ” 2 ” 5. ” ” 6 ” 2 ” 6. ” ” 3 ” 7 » 7. ” ”» 10 ” 0 ” 8. ” ” 4 » 6 y 9. ” ” 1 ” 0 wm 10. a porcelain 0 zs 10 a 11. 5) red glass 10 ” 0 mn 12. er porcelain 4 “ 6 af 13. 3 red glass 7 BY 3 “é 14, 6 porcelain 4 » 6 ws 15. 36 red glass 4 a 6 3 16. a porcelain 0 i 10 9 17. ai red glass 10 Sy 0 ‘3 18, $5 ” 8 ” 2 » 19. é porcelain 7 ie 3 ss 20 ” ” 1 ” 9 ” Total ... a. 90 88 Obviously, therefore, the ants showed no marked preference for the porcelain. On one, but only on one occasion (Obs. 9), most of the pupz were carried under the violet. glass, but generally it was quite neglected. I now tried a similar experiment with porcelain and yellow glass. Obs. 8 {Pape were taken 9 { under under yellow. porcelain 2. ” ” 2 » 8 ” 3. ” ” 8 ” 2 » 1. Qucen went under porcelain 198 EXPERIMENTS WITH SLECTRUM. Obs 4. Queen wen* under yellow glass 5 | i ae Nai ren 5 { rents 6 + porcelain 8 is 8 ” 6. os yellow glass 8 ‘3 3 » 7 as porcelain 6 55 5 + 8 ” ” 0 ” 7 » 9, Fr ” 0 ” 10 » 10 a5 yellow glass 5 ‘i 5° og 11. e porcelain 8 * 2 % 12. ” » 3 2 7 ” 13. ” yellow glass 10 Pe 0 9 14. + porcelain 0 s9 10 oe 15. ” yellow glass 10 55 0 PP 16. ” ” 7 ” 3 ” 17. ” ” 10 ” 0 » 18. 7 porcelain 1 3 9 ‘9 19. ‘5 7 0 ” 10 ” 98 92 The porcelain and yellow glass seemed, therefore, to affect the ants almost equally. I then put two ants on a paper bridge, the ends supported by pins, the bases of which were in water. The ants wandered backwards and forwards, endea- vouring to escape. I then placed the bridge in the dark and threw the spectrum on it, so that succes- sively the red, yellow, green, blue, and violet fell on the bridge. The ants, however, walked backwards and forwards without (perhaps from excitement) taking any notice of the colour. I then allowed some ants (Lasius niger) te find some larve, to which they obtained access over a narrow paper bridge. When they had got used to it, LIMITS OF VISION. , 199 I arranged so that it passed through a dark box, and threw on it the principal colours of the spectrum, namely, red, yellow, green, blue, and violet, as well as the ultra-red and ultra-violet; but the ants took no notice. : It is obvious that these facts suggest a number of interesting inferences. I must, however, repeat the observations and make others; but we may at least, I think, conclude from the preceding that:—(1) ants have the power of distinguishing colours; (2) that they are very sensitive to violet; and it would also seem (3) that their sensations of colour must be very different from those produced upon us. But I was anxious to go beyond this, and to attempt to determine how far their limits of vision are the same as ours. We all know that if a ray of white light is passed through a prism, it is broken up into a beautiful band of colours—the spectrum. To our eyes this spectrum is bounded by red at the one end and violet at the other, the edge being sharply marked at the red end, but less abruptly at the violet. But a ray of light contains, besides the rays visible to our eyes, others which are called, though not with absolute correctness, heat-rays and chemical rays. ‘These, so far from falling within the limits of our vision, extend {sr beyond it, the heat-rays at the red, the chemical raye at the violet end. I have tried various experiments with spectra derived from sunlight; but, owing to the rotation of 200 THE ULTRA-RED AND ULTRA-VIOLET RAYS. the earth, they were not thoroughly satisfactory. Mr. Spottiswoode was also good enough to enable me to make some experiments with electric light, which were not very conclusive; more recently I have made some additional and much more complete experiments, through the kindness of Prof. Dewar, Prof. Tyndall, and the Board of Managers of the’ Royal Institution, to whom I beg to offer my cordial thanks. Of course, the space occupied by the visible spec trum is well marked off by the different colours, Beyond the visible spectrum, however, we have no such convenient landmarks, and it is not enough to describe it by inches, because so much depends on the prisms used. If, however, paper steeped in thalline is placed in the ultra-violet portion of the spectrum, it gives, with rays of a certain wave-length, a distinctly visible green colour, which therefore constitutes a green band, and gives us a definite, though rough, standard of measurement. In the above experiments with coloured spectra, the ants carried the pupx out of the portion of the nest on which coloured light was thrown and deposited them against the wall of the nest; or, if I arranged 1 nest of Formica fusca so that it was entirely in the light, they carried them to one side or into one corner. It seemed to me, therefore, that it would be interesting so to arrange matters, that on quitting the spectrum, after passing through a dark space, the ants should encounter not a solid obstacle, but a barrier of light. With this EXPERIMENTS WITH ELECTRIC LIGHT. 201 object, I prepared some nests 12 inches long by 6 inches wide; and Mr. Cottrell kindly arranged for me at the Royal Institution on the 29th of June, by means of the electric light, two spectra, which were thrown by two glass prisms on to a table at an angle of about 45°. Each oceupied about 6 inches square, and there was a space of about 2 inches between them—that is, between the red end of the one and the violet of the other. Experiment 1.—In one of the spectra I placed a nest of Formica fusca, 12 inches by 6, containing about 150 pupe, and arranged it so that one end was distinctly beyond the limit of the violet visible to us, and all but to the edge of the green given by thalline paper, and the other just beyond the visible red. The pup at first were almost all in or beyond the violet, but were carricd into the dark space between the two spectra, the bright thalline band being avoided, but some pupz being deposited in the red. Experiment 2.—I then tried the same experiment with a nest of Lasius niger, in which there were many larvee as well as pup. They were all at the commence- ment at the blue end of the nearer spectrum. The larvee were left by themselves in the violet, while pups were ranged from the end of the green to that of the red inclusive. Experiment 3.—Arranged a nest of L. niger as before ; at the commencement the pupe and larve were much scattered, being, however, less numerous in the violet and ultra-violet rays. Those in the ultra-violet 15 202 EXPERIMENTS WITH ELECTRIC LIGHT. rays were moved first, and were deposited, the larve in the violet, and the pupz in the red. Experiment 4.—Made the same experiment with another nest of L. niger. At the commencement the larve aad pupe were in the violet and ultra-violet portion, extending to double the distance from the visible end to the thalline band. The ants soon began bringing the pupe to the red. Over part of the red I placed a piece of money. The pupe were cleared from the ultra-violet first. That the pupz were not put in the red for the sake of the red light was evident, because the space under the coin was even more crowded than the rest. The pups were heaped up in the dark as far as the thalline band of the other spec- trum. J then brought the second spectrum nearer to the first. The pups which thus came to be in the thalline band were gradually moved into the dark. Experiment 5.—Tried the same with another nest of L. niger. The pup were at first in the violet and ultra-violet about double as far as the thalline line, while most of the larve were in the green. The furthest part was cleared first; and they were again brought principally into the yellow, red, and dark. Again, I scattered them pretty equally, some being ia the ultra-violet portion, as far as double the distance of the thalline from the violet; most, however, being in the violet and blue. The ants began by removing the pupe which were EXPERIMENTS WITH ELECTRIC LIGHT. 203 in and near the thalline band, and carried them into the yellow or red. Experiment 6.—Repeated the same experiment. Begun it at 11.15. Placed some pupe in the red, some in the yellow, and a few scattered over the second apectrum; there were none in the nearer one. They were all carried away from the red past the violet, and put down in the dark portion, or in the red and yellow, of the nearer spectrum. These experiments surprised me much at the time, as I had expected all the pupe to be carried into the space between the two spectra; but it afterwards occurred to me that the ultra-violet rays probably extended further than I had supposed, so that even the part which lay beyond the thalline band contained enough rays to appear light to the ants. Hence perhaps they selected the red and yellow as a lesser evil. Experiment 7.—I altered, therefore, the arrange- ment. Prof. Dewar kindly prepared for me a con- densed pure spectrum (showing the metallic lines) with a Siemens’ machine, using glass lenses and a mirror to give a perpendicular incidence when thrown on the nest. I arranged the pupe again in the ultra-violet as far as the edge of the fluorescent light shown with thalline paper. The pup were all again removed, and most of them placed just beyond the red, but none in the red or yellow. Experiment 8.—Arranged the light as before, and placed the pup in the ultra-violet rays. In half an 204 EXPERIMENTS WITH ELECTRIC LIGHT. hour they were all cleared away and carried into the dark space beyond the red. We then turned the nest round so that the part occupied by the pupz again came to be in the violet and ultra-violet. The light chanced to be so arranged that along one side of the nest was a line of shadow ; and into this the pupe were carried, all those in the ultra-violet being moved. We then shifted the nest a little, so that the violet and ultra-violet fell on some of the pupx. These were then all carried into the dark, the ones in the ultra-violet being moved first. In these experiments with the vertical incidence there was less diffused light, and the pupz were in no case carried into the red or yellow. Experiment 9.—I arranged the light and the ants as before, placing the pupe in the ultra-violet, some being distinctly beyond the bright thalline band. The ants at once began to remove them. At first many were deposited in the violet, some, however, being at once carried into the dark beyond the red. When all had been removed from the ultra-violet, they directed their attention to those in the violet, some being carried, as before, into the dark, some into the red and yellow. Again, when those in the violet had all been removed, they began on the pupe in the red and yellow, and carried them also into the dark. This took nearly half an hour. As I had arranged the pupe so that it might be said that they were awkwardly placed, we then turned the nest round, leaving the pup otherwise as they had been arranged by the ants; but the result of ANTS NOT SENSITIVE TO ULTRA-RED RAYS. 208 moving the nest was to bring some of them into the violet, though most were in the ultra-violet. They were, as before, all carried into the dark space beyond the red in about half an hour. We then turned the glass round again, this time arranging the end about the length of the spectrum beyond the end of the violet visible to oureyes. They began clearing the thalline band, carrying some into the violet, but the majority away further from the spectrum. In a quarter of an hour the thalline band had been quite cleared; and in half an hour a band beyond, and equal to the thalline band, those in the violet being left untouched. After the pupe in the ultra-violet portion had all been moved, those in the violet. were also carried away and deposited about twice as far from the edge of the violet as the further edge of the bright thalline band. Experiment 10.—Experimented again with the same arrangement as before, using another nest of Lasius niger and placing the pupe in the violet and a little beyond. The ants at once began removing them into the dark, tunnelling into the heap, and then carry- ing away those in the ultra-violet first, although they were further off. In half an hour they had all been moved out of the violet and ultra-violet, about half being placed in the dark, and half having been pro- visionally deposited in the red and yellow. Experiment 11.—Same arrangement as before. The pupe being placed all along one side of the nest, 206 ANTS NOT SENSITIVE TO ULTRA-RED RAYS, from the edge of the red to a distance beyond the violet as great as the whole length of the spectrum. I began at 4.15. By degrees they were all cleared away from the spectrum, except those in the violet, where indeed, and immediately outside of which, the others were placed. At 5, however, they began to carry them back into the red. At 5.45 the blue and violet were nearly cleared, the pupe being placed in the red and yellow. At 6.15 they had all been brought from the violet and ultra- violet into the red and yellow. I then shook up the pups so that they were arranged all along one side of the nest, and extended about an inch beyond the red. This excited the ants very much, and in less than ten minutes all those in the spectrum, and for about 6 inches beyond the violet, were moved, but at first they were put down anywhere, so that they were scattered all over the nest. This, however, lasted for a very short time, and they were all carried into the dark beyond the red, or into the extreme end at some distance beyond the violet. At 7 the edge of the heap of pupz followed the line of the red at one end, coming about } inch within it, which was not owing to want of room, as one side of the nest was almost unoccupied; at the other end they were all carried 3 inches beyond the end of the violet. It would seem, then, as the result of these experi- ments, that the limits of vision of ants at the red end of the spectrum are approximately the same as ours, that they are not sensitive to the ultraered BUT VERY SENSITIVE TO ULTRA-VIOLET RAYS, 207 rays; but, on the other hand, that they are very sen- sitive to the ultra-violet rays, which our eyes cannot perceive. I then arranged the same ants in a wooden frame consisting of a base and two side walls, between which in the middle was a perpendicular sliding door. The pupe had been arranged by the ants in the centre of the nest, so that some were on each side of the door. We then threw, by means of a strong induction-coil, a magnesium-spark on the nest from one side, and the light from a sodium-flame in a Bunsen burner on the other, the light being in each case stopped by the sliding door, which was pressed close down on the nest. In this way the first half was illuminated by the one light, the second by the other, the apparatus being so arranged that the lights were equal to our eyes—tLat, however, given by the magnesium, consisting mainly of blue, violet, and ultra-violet rays, that of the sodium being very yellow and poor in chemical rays. In a quartei of an hour the. pup were all carried into the yellow. The sodium light being the hotter of the two, to eliminate the action of heat I introduced a water-cell between the ants and the sodium-flame, and made the two sides as nearly as possible equally light to my eye. The pupe, however, were again carried into the sodium side. I repeated the same experiment as before, getting the magnesium-spark and the sodium-flame to the same degree of intensity, as nearly as my eye could judge, 208 EXPERIMENTS WITH MAGNESIUM SPARK and interposing a water-screen between the sodium- flame and the ants. The temperature was tested by the thermometer, and I could distinguish no difference between the two sides. Still the ants preferred the solium side. This I repeated twice. I then removed the magnesium-spark somewhat, so that the illumina- tion on that side was very much fainter than on the other; still the pups were carried into the sodium- light. I then turned the nest round so as to bring them back into the magnesium. They were again carried to the sodium side. Once more I repeated the same experiment. The light on the magnesium side was so faint that I could scarcely see the pupz, those on the sodium side being quite plain. The thermometer showed no difference between the two sides. The pups were carried into the sodium-light. Ithen turned the nest round twice ; but the pupze were each time carried out of the magnesium-light. These experiments seemed strongly to indicate, if not to prove, that ants were really sensitive to the ultra-violet rays. Now to these rays sulphate of quinine and bisulphide of carbon are extremely onaque, though perfectly transparent in the case of visible rays, and therefore to our eyes entirely colourless and trans- parent. If, therefore, the ants were really affected by the ultra-violet rays, then a cell containing a layer of sulphate of quinine or bisulphide of carbon would tend to darken the underlying space to their eyes, though to ours it would not do so. AND SODIUM FLAME. 209 It will be remembered that if an opaque substance is placed over a part of a glass nest, other things being equal, the ants always congregate under it ; and that if substances of different opacity are placed on different parts of a nest, they collect under that which seems to them most opaque. Over one of my nests of Formica fusca, therefore, I placed two pieces of dark-violet glass 4 inches by 2 inches; and over one of them I placed a cell containing a layer of bisulphide of carbon, an inch thick, slightly coloured with iodine. In all these experi- ments, when I. moved the liquids or glasses, I gave the advantage, if any, to the one under which experi- ence showed that the ants were least likely to congre- gate. The ants all collected under the glass over which was the bisulphide of carton. I then thought that though no doubt the iodine rendered the bisulphide more completely impervious to the ultra-violet rays, I would: try the effect of it when pure and perfectly colourless. I therefore tried the same experiment with pure bisulphide, moving the two glasses from time to time in such a manner that the ants had to pass the first violet glass in order to reach that over which was the bisulphide. At &30 the ants were all under the glass over which was the bisulphide of carbon: I then changed the position. 8.45 bP) +P) ” 9 ” » ” 9.15 » ” ” 210 EXPERIMENTS WITH Although the bisulphide of carbon is so perfectly transparent, [ then thought I would try it without the violet glass. I therefore covered part of the nest with violet glass, a part with a layer of bisulphide of carbon, moving them from time to time as before, and the ants in every case went under the bisulphide. I then reduced the thickness of the layer of bisul- phide to ;4; of an inch, but still they preferred the disulphide. Then thinking that possibly the one shelter being a plate of glass and the other a liquid might make a difference, I tried two similar bottles, one contain- ing water and the other bisulphide of carbon; but in every case the ants went under the bisulphide of carbon. On the other hand, when I used coloured solu- tions so deep in tint that the ants were only just visible through them, the ants went under the coloured liquids. October 10.--I uncovered the nest at 7 A.M., giving the ants an option between the bisulphide of carbon and various coloured solutions, taking for violet am- monio-sulphate of copper ; for red, a solution of carmine go deep in tint that the ants could only just be seen through it ; for green, a solution of chlorate of copper ; and for yellow, saffron. They were each separately tried with the bisulphide, and in every case the ants preferred the coloured solution. I now took successively red, yellow, and green glass; but in every case the ants preferred the glass to the bisulphide. Although, therefore, it would seem BISULPHIDE OF CARBON. 211 from the previous experiments that the bisulphide darkened the nests to the ants more than violet glass, it would appear to do so less than red, green, or yellow I now made some experiments in order, if possible, to determine whether the reason why the auts avoided the violet glass was because they disliked the colour violet, or whether it was because the violet glass trans- mitted more of the ultra-violet rays. For this purpose I placed a layer of the bisulphide of carbon over a piece of violet glass. By this arrange- ment I got the violet without the ultra-violet rays ; and I then contrasted this combination with other coloured media. : First, I took a solution of bichromate of potash (bright orange), and placed it on a part of the nest, side by side with the violet glass and bisulphide of carbon. I should add that the bichromate of potash also cuts off the ultra-violet rays. In all the following observations I changed the position after each observation. At 1.30 p.m. the ants were under the bichromate. 3 ss es half under the bichromate and half under the violet glass and bisulphide. 8 AM. 55 » under the bichromate. 8.30 55 45 under the violet glass and bisulphide. 9 5 » half under each. 9.80 ss 3 some under each, but most 212 EXPERIMENTS WITH under the violet glass and bisulphide. 9.45 a a half under each. 10 ” ” bd bb) In this case, therefore, though without the layer of bisulphide the violet glass would always have been avoided, the result of placing the bisulphide over the violet glass was that the ants did not care much whether they were under the violet glass or under the bichromate of potash. I then took the same solution of carmine which T oad already used. 10. The ants were under the carmine. 10.15 ” ” cy) 10.30 i most under the carmine, but some under the violet. 10.45 Pe under the carrine. 11. 5 most under the carmine, but some under the violet. Here, then, again the bisulphide made a distinct difference, though not so much so as with the bichro- mate of potash. I then took the solution of chlorate of copper aready used. 1 About half the an's were under each, 1.30. The greater number were under the violet glass and bisulphide. BISULPHIDE OF CARBON. 213 2. The greater number were under the violet glass and bisulphide. 2.30 ” a9 ” 3. Almost all were under the glass and bis::Iphide, The addition of the bisulphide thus caused the violet glass to be distinctly preferred to the chlorate of copper. I then took a solution of sulphate of nickel, almost exactly the same tint as, or a shade paler than, the chlorate of copper. At 3.45 the ants were under the violet glass and bisulphide. 4. » 3 ” 5. ” ” ” October 18. TAM. 55 ” ” 8. About half of the ants were under each. Here the effect was even more marked. I then took some saffron 1 inch in thickness and of u deep-yellow colour. 12.45 The ants were about half under each. 1. Most of the ants were under the violet glass and bisulphide. 1.15 ” ” ” 2. Most of the ants were under the saffron. Here, again, we have the same result. I then tried the different-coloured glasses, all of which, as I had previously found, are unmistakably preferred to the violet. It remained to be seen what 214 EXPERIMENTS WITH . effect placing the bisulphide of carbon on the violet would have. First, I placed side by side, as usual, a piece of green glass and the violet glass covered with bisuly nide of carbon :— [st exp. Half of the ants were under each. 2nd ,, They were under the violet glass and bisulphide. 3rd_,, »” ” ” 4th exp. Most of them were under the violet glass and bisulphide. 5th 9 33 9 2 Next, I tried pale-yellow glass. Ist obs. The ants were almost all under the violet glass and bisulphide. 2nd ,, About three-quarters were ,, 3 3rd_,, They were all 8 9 4th ,, About half were under each. I then took the dark-yellow glass. Ist obs. About half the ants were under the yellow glass and half under the viclet glass and bisulphide. znd ,, Most of them were under the violet glass and bisulphide. 3rd ,, * 55 yellow glass. 4th ,, a % violet glasa and bisulphide. 6th ,, About half under each. BISULPHIDE OF CARBON, 215 I now took deep-red glass. 1st obs, The ants were under the red glass. 2nd ,, Half of the ants were under each. 3rd _,, Most of the ants were under violet glass and bisulphide. 4th ,, Half were under each. It seemed evident, therefore, that while if violet glass alone was placed side by side with red, yellow, or green, the ants greatly preferred any of the latter, on the other hand, if a layer of bisulphide of carbon, which to our eyes is perfectly transparent, was placed over the violet glass, they then went as readily, or even more readily, under it than under other colours. In order to be sure that it was not the mere presence of a fluid, or the two layers of glass, to which this was due, I thought it would be well to try a similar series of expcriments, using, however, a layer of similar thickness (1 inch) of water coloured light blue by ammonio-sulphate of copper. I therefore took again the piece of violet glass, over which I placed a flat-sided bottle, about 1 inch thick, containing a light-blue solution of ammonio-sulphate of copper; and, in contrast with it, I used the same coloured glasses as before. The difference, however, was very marked, the ants always preferring the red, green, and yellow to the violet. These experiments seem to demonstrate that in the previous series the ants were really influenced by 216 EXPERIMENTS WITH some difference due to the bisulphide of carbon, which affected their eyes, though not ours. I then thought it would be interesting to use, instead of the bisulphide, a solution of sulphate of quinine (4 dr. to 4 ounces), which differs from it in many points, but agrees in cutting off the ultra-violet rays. I used, as before, a layer about an inch thick, which I placed over violet glass, and then placed by its side the same coloured glasses as before. First, I took the red glass. Obs. 1. About half the ants were under each. »» 2. Most of them were under the red glass. » 3. About half under each; rather more under the violet glass and sulphate of quinine than under the red glass. ” 4. 29 + ” I now took the dark-yellow glass instead of the red. Obs. 1. Most of the ants were under the violet glass and sulphate of quinine, i ee All Pe 5 ‘s ” 3. PD ” 9 ” 9 Se 9 9 » yellow glass. ” 5. 29 9 ” ” », 6. All the ants were under the violet glass and sulphate of quinine. y “@. About half under each. n 8. Rather more under the violet glass and sulphate of quinine than under the yellow glass. BISULPHIDE OF CARBON. 217 I then took the light- yellow glass instead of the dark. bs. 1. The ants were ail under the violet glass and sulphate of quinine. » 2. Rather more than half under tne yellow glass. », 3- Almost all under the violet glass and sulphate of quinine. » 4. All ” ” ” ” I then took the green glass instead of the yellow. Obs. 1. They were under the violet glass and sulphate of quinine. oe ” ” ” 3. About half under each. 4. About three-quarters under the green glass. 5. Almost all under the violet glass and sulphate of quinine. 39 ” ” Thus, then, while if the ants have to choose between the violet and other coloured glasses, they will always prefer one of the latter, the effect of putting over the violet glass a layer either of sul- phate of quinine or bisulphide of carbon, both of which are quite transparent, but both of which cut off the ultra-violet rays, is to make the violet glass seem to the ants as good a shelter as any of the other glasses. This seems to me strong evidence that the ultra-violet rays are visible to the ants. I then tried similar experiments with a saturated solution of chrome alum and chromium chloride. These 16 218 CHROME ALUM AND CHROMIUM CHLORIDE. are dark greenish blue, very opaque to the visible light-rays, but transparent to the ultra-violet. I used a Jayer } inch thick, which was still so dark that I could not see the ants through it; and for comparison, a solution 1 inch thick of bisulphide of carbon, moving them after each observation as before. Exp. 1. The ants were under the bisulphide of carbon. ” 2. 99 ” 2 Exp. 3. Most of the ants were under the bisulphide of carbon. » 4. All but three » ” » All ” ” T now took chromium chloride instead of alum. Exp. 1. Most were under the bisulphide of carbon. 9 2. All ” ” ” » 3. Almost all ,, si » 4. About three-fourths were igaee the chromium chloride. . All were under the chromium chloride. . About two-thirds is . About one-half under each. . All under the bisulphide of carbon. . About three-fourths under the bisulphide _ of carbon. 10. About half ,, 4 se y 11. All under the chrome alum. ov 22s ss bisulphide of carbon. ” ” 29 . oOnrwTr an © 9 3 ANTS SENSITIVE TO ULTRA-VIOLET RAYS. 219 This result is very striking. It appears to show that though to our eyes the bisulphide of carbon is absolutely transparent, while the chrome alum and chromium chlo- ride are very dark, to the ants, on the contrary, the former appears to intercept more light than a layer of the latter, which to our eyes appears dark green. The only experiments hitherto made with the view of determining the limits of vision of animals have been some by Prof. Paul Bert! on a small fresh-water crustacean belonging to the genus Daphnia, from which he concludes that they perceive all the colours known to us, being, however, specially sensitive to the yellow and green, and that their limits of vision are the same as ours. Nay, he even goes further than this, and feels justified in concluding from the experience of two widely divergent species—Man and Daphnia —that the limits of vision would be the same in all cases. His words are — A. ‘Tous les animaux voient les rayons spectraux que nous voyons.’ B. ‘Ils ne voient aucun de ceux que nous ne voyons pas.” C. ‘Dans l’étendue de la région visible, les différ- ences entre les pouvoirs éclairants des différents rayons coloriés sont les mémes pour eux et pour nous.’ He adds, that ‘puisque les limites de visibilités semblent étre les mémes pour les animaux et pour nous, ' Archiv. de Physiol. 1869, p. 547. 2206 THE SENSE OF COLOUR. ne trouvons-nous pas la une raison de plus pour supposer que le réle des milieux de l’ceeil est tout-a-fait secondaire, et que la visibilité tient 4 l’impressionnabilité de l’appareil nerveux lui-méme ?’ Such a generalisation would seem to rest on but a slight foundation ; and I may add that I have made some experiments myself! on Daphnias which do not agree with those of M. Bert. On the contrary, I believe that the eyes of Daphnias are in this respect constituted like those of ants. ‘These experiments seem {o me very interesting. They appear to prove that ants perceive the ultra-violet rays. Now, as every ray of homogeneous light which we can perceive at all appears to us as a distinct colour, it becomes probable that these ultra-violet rays must make themselves apparent to the ants as a distinct and separate colour (of which we can form no idea), but as unlike the rest as red is from yellow, or green from violet. The question also arises whether white light to these insects would differ from our white light in containing this additional colour. At any rate, as few of the colours in nature are pure, but almost all arise from the combination of rays of different wave- lengths, and as in such cases the visible resultant would be composed not only of the rays which we see, but of these and the ultra-violet, it would appear that the colours of objects and the general aspect of nature § British Assoc. Report 1881, and Linnean Soc. Journ. 1882 THE SENSE OF HEARING. 291 must present to them a very different appearance from what it does to us. The Sense of Hearing. Many eminent observers have regarded the antenna of insects as auditory organs, and have brought forward strong evidence in favour of their view. I have myself made experiments on grasshoppers, which convinced me that their antenne serve as organs cf hearing. So far, however, as Ants, Bees, and Wasps are con- cerned, the evidence is very conflicting. The power of hearing has indeed generally been attributed to them. Thus St. Fargeau, in his ‘ Hist. Nat. des Hyménoptéres,’! thinks there can be no doubt on the subject. Bevan expresses, no doubt, the general opinion with reference to Bees, when he says that ‘ there is good evidence that Bees have a quick sense of hearing.’ ? As regards Wasps, Ormerod, who studied them so lovingly, came to the same conclusion.? On the other hand, both Huber‘ and Forel ® state that ants are quite deaf. As I have already men- tioned in the ‘Linnean Journal’ (vols. xii. and xiii.), 1 have never succeeded in satisfying myself that my ants, bees, or wasps heard any of the sounds with 1 Vol. i. p. 113. 2 The Honey Bee, p. 264. ® Nat. Hist. of Wasps, p. 72. 4 Nat. Hist. of Ants. 5 Fourmis de la Suisse, p. 121. 223 THE SENSE OF HEARING. which 1 tried them. I have over and over again tested them with the loudest and shrillest noises I could make, using a penny pipe, a dog-whistle, a violin, as well as the most piercing and startling sounds I could produce with my own voice, but all without effect. At the same time, I carefully avoided inferring from this that they are really deaf, though it certainly seems that their range of hearing is very different from ours. In order, if possible, to throw some light upon this interesting question, I made a variety of loud noises, including those produced by a complete set of tuning-forks, as near as possible to the ants mentioned in the preceding pages, while they were on their journeys to and fro between the nests and the larve. In these cases the ants were moving steadily and in a most business-like manner, and any start or alteration of pace would have been at once apparent. I was never able, however, to perceive that they took the slightest notice of any of these sounds, Thinking, however, that they might perhaps be too much absorbed by the idea of the larve to take any notice of my interruptions, I took one or two ants at random and put them on a strip of paper, the two ends of which were supported by pins with their bases in water. The ants imprisoned under these circumstances wandered slowly backwards and forwards along the paper. As they did so,I tested them in the same manner as before, but was unable to perceive that they APPARENT DEAFNESS OF ANTS. 223 took the slightest notice of any sound which I was able to produce. I then took a large female of F. ligniperda, and tethered her on a board to a pin by a delicate silk thread about 6 inches in length. After wandering about for a while, she stood still, and I then tried her in the same way; but, like the other ants, she took no notice whatever of the sounds. It is of course possible, if not probable, that ants, even if deaf to sounds which we hear, may hear others to which we are deaf. Having failed, therefore, in hearing them or making them hear me, I endeavoured to ascertain whether they could hear one another. To ascertain then if possible whether ants have the power of summoning one another by sound, I tried the following experiments. I put out (Sept. 1874) on the board where one of my nests of Lasius flavus was usually fed, six small pillars of wood about an inch and a half high, and on one of them I put some honey. A number of ants were wandering about on the board itself in search of food, and the nest itself was immediately above, and about 12 inches from, the board. I then put three ants to the honey, and when each had sufficiently fed I imprisoned her and put another; thus always keeping three ants at the honey, but not allowing them to go home. If then they could summon their friends by sound, there ought soon to be many ants at the honey. The resulta were as follow: 224 ATTEMPTS TO ASCERTAIN September 8.—Began at 11 am. Up to 3 o'clock only seven ants found their way to the honey, while about as many ran up the other pillars. The arrival of these seven, therefore, was not more than would naturally result from the numbers running about close by. At 3 we allowed the ants then on the honey to return home. The result was that from 3.6, when the first went home, to 3.30, eleven came; from 3.30 to 4, no less than forty-three. Thus in four hours only seven came, while it was obvious that many wouid have wished to come, if they had known about the honey, because in the next three quarters of an hour, when they were informed of it, fifty-four came. On September 10 I tried the same again, keep- ing as before three ants always on the honey, but not allowing any to go home. From 12 to 5.30, only eight came. Those on the honey were then allowed to take the news home. From 6.30 to 6, four came; from 6 to 6.30, four ; from 6.30 to 7, eight; from 7.30 to 8, no less-than fifty-one. On September 23 we did the same again, begin- ning at 11.15. Up to 3.45 nine came. The ants on the honey were then allowed to go home. From 4 to 4.30 nine came; from 4.30 to 5, fifteen; from 5 to 5.30 nineteen; from 5.30 to 6, thirty-eight. Thus in three and a half hours only nine came 3; in two, when the ants were permitted to return, eighty-one. Again, on September 301 tried the same arrange- ment, again beginning at 11. Up to 3.30 seven anty WHETHER ANTS CALL ONE ANOTHER. 225 eame. We then allowed the ants which had fed to go home. From 3.30 to 4.30 twenty-eight came. From 4.30 to 5, fifty-one came. Thus in four hours and a half only seven came; while when the ants were allowed to return no less than seventy-nine came in an hour and a half. It seems obvious therefore that in these cases no communication was transmitted by sound. Again, Professor Tyndall was good enough to arrange for me one of his sensitive flames; but I could not perceive that it responded in any waytomyants. The experiment was not, however, very satisfactory, as I was not able to try the flame with a very active nest. Professor Bell most kindly set up for me an extremely sensitive microphone : it was attached to the underside of one of my nests; and though we could distinctly hear the ants walking about, we could not distinguish any other sound. It is, however, far from improbable that ants may produce sounds entirely beyond our range of hearing. Indeed, it is not impossible that insects may possess senses, or sensations, of which we can no more form an idea than we should have been able to conceive red or green if the human race had been blind. The human ear is sensitive to vibrations reaching at the outside to 38,000 in a second. The sensation of red is produced when 470 millions of millions of vibrations enter the ‘eye in a similar time; but between these two numbers, vibrations produce on us only the sensation of heat; 226 EXPERIMENTS WITH SENSITIVE FLAME. we have no special organs of sense adapted to them There is, however, no reason in the nature of things why this should be the case with other animals; and the problematical organs possessed by many of the lower forms may have relation to sensations which we do not perceive. If any apparatus could be devised by which the number of vibrations produced by any given cause could be lowered so as to be brought within the range of our ears, it is probable that the result would be most interesting. Moreover, there are not wanting observations which certainly seem to indicate that ants possess some sense of hearing. I am, for instance, indebted to Mr. Francis Galton for the following quotation from Colonel Long’s recent work on Central Africa.! ‘I observed,’ he says, ‘the manner of catching them’ (the ants, for food), ‘as here pictured’ (he gives a figure). ‘Seated round an ant- hole were two very pretty maidens, who with sticks beat upon an inverted gourd, “bourmah,” in cadenced time to a not unmusical song, that seduced from its hole the unwary ant, who, approaching the orifice, was quickly seized.’ The species of ant is not mentioned. Moreover, there are in the antenne certain remark- able structures, which may very probably be auditory wgans. These curious organs (Fig. 6) were first noticed, ' Central Africa, by Col, C, O. Long, p. 274, ANTS PROBABLY HEAR HIGH NOTES 227 so far as [ am aware, by Dr. J. Braxton Hicks in his ex« cellent paper on the ‘Antenne of Insects,’ published in the 22nd volume of the ‘Linnzan Transactions ;’ and, again, by Dr. Forel in his ‘Fourmis de la Suisse.’ They certainly deserve more attention than they have yet received. The cork-shaped organs (Figs. 6 and 7, ¢e) occur in allied species; but these stethoscope-like organs have not, so far as I am aware, been yet observed in other insects. They consist of an outer sac (Figs. 6 and 7, s), of a long tube (t), and a posterior zhamber (w), to which is given a nerve (7). Forel! also describes these curious organs. He appears to consider that the number varies consider- Terminal portion of antenne of Myrmica ruginodis $ x 75 ably, namely, from 5 to 12. My own impression is that this difference is only apparent, and that in reality the numbers in each species vary little. Though 1 Trans. of Linnean Soc., vol. xxii. p. 391. 3 Fourmis de la Suisse, p. 301. 228 ORGANS OF SENSE sometimes the presence of air renders them ery con- spicuous, they are in others by no means easy to make Fig. 7. n w Diagrammatic section through part of Fig. 6. e, chitinous skin of the antenna. ee, two of the cork-shaped organs. 8, external chamber of one of the stethoscope-shaped organs. 7%, the tube. w, the posterior sac. n, the nerve. out ; and I think that when a small number only are apparently present, this is probably due merely to the fact that the others are not brought out by the mode of preparation. In addition to the group of these organs situated in the terminal segment, there is one, or in some rare cases I have found two, in each of the small preceding segments. The tubes in these segments appeared to the eye to be nearly of the same length as those in the terminal segment, but I could not measure their exact length, as they do not lie flat. In some cases, when the segment was short, the tube was bent—an indica- tion, perhaps, that the exact length is of importance. It is possible that these curious organs may be audi- tory, and serve like microscopic stethoscopes. Professor Tyndall, who was good enough to examine them with me, concurred in the opinion that this was very pro- bable. I believe I am correct in saying that the bend- IN CHE ANTENNAS OF ANTS. 229 ing of the tube in the short segments would make little difference in its mode of action. Kirby and Spence were, I believe, the first to notice that an insect allied to the ants (Mutilla Europea) has the power of making a sibilant, chirping sound, but they did not ascertain how this was effected. Goureau! subsequently called at- tention to the same fact, and attributed it to fric- tion of the base of the third segment of the abdo- men against the second. Westwood,? on the other hand, thought the sound was produced ‘ by the action of the large collar against the front of the mesothorax. Darwin, in his ‘ Descent of Man,’ adopts the same view. ‘I find,’ he says, ‘that these surfaces (i.e. the over- lapping portions of the second and third abdominal segments) are marked with very fine concentric ridges, but so is the projecting thoracic collar, on which the head articulates; and this collar, when scratched with the point of a needle, emits the proper sound.’ Landois, after referring to this opinion, expresses himself strongly in opposition to it. The true organ of sound is, he maintains,‘ a triangular field on the upper surface of the fourth abdominal ring, which is finely ribbed, and which, when rubbed, emits a stridulating sound. It certainly would appear, from Landois’ observations, that this structure does produce sound, whether or not 1 Ann, de la Soc. Ent. de France, 1837. 2 Modern Classifications of Insects, vol, ii. § Descent of Man, vol. i. p. 366. § Thierstimmen, p. 132. 230 STRIDULATING APPARATUS we consider that the friction of the collar against the mesothorax may also assist in doing so. Under these circumstances, Landois asked himself whether other genera allied to Mutilla might not possess a similar organ, and also have the power of pro- ducing sound. He first examined the genus Ponera, which, in the structure of its abdomen, nearly resem- bles Mutilla, and here also he found a fully developed stridulating apparatus. He then turned to the true ants, and here also he found a similar rasp-like organ in the same situation. It is indeed true that ants produce no sounds which are audible by us; still, when we find that certain allied insects do produce sounds appreciable to us by rubbing the abdominal segments one over the other; and when we find, in some ants, a nearly similar structure, it certainly seems not unreasonable to conclude that these latter also do produce sounds, even though we cannot hear them. Landois describes Fig. 8. Cs Attachment of abdominal segments of Lasius flavus ¥ x 225. the structure in the workers of Lasius fuliginosus as naving 20 ribs in a breadth of 0°13 of a millimetre, ON ABDOMINAL SEGMENTS. 231 but he gives no figure. In Fig. 8 I have represuuted the junction of the second and third abdominal seg- ments in Lasius flavus, x 225, as shown in a longi- tudinal and vertical section. There are about ten well-marked ribs (r), occupying a length of approxi- mately 54, of an inch. Similar ridges also occur between the following segments. In connection with the sense of hearing I may mention another very interesting structure. In the year 1844, Von Siebold described! a remarkable organ which he had discovered in the tibie of the front legs of Gryllus,and which he considered to serve for the pur- pose of hearing. These organs have also been studied by Burmeister, Brunner, Hensen, Leydig, and others, and have recently been the subject of a monograph by Dr. V. Graber,’ who commences his memoir by observ- ing that they are organs of an entirely unique character, Fig. 9. Tibia of Lasius flavus § x 75. and that nothing corresponding to them occurs in any other insects, or indeed in any other Arthropods. 1 See also Sharp, 77rans. Ent. Soc., 1893. 2 Ueber das Stimm. und Gehérorgan der Orthopteren, Wiegmann’s Art. f. Natur., 1844. 3 Die Tympanalen Si pparate der Orthopteren, von Dr. Vitus Graber, 1875. 232 REMARKABLE STRUCTURE IN I have tnerefore been very much interested by die covering (1875) in ants a structure which seems in some remarkable points to resemble that of the Orthoptera. As will be seen from a glance at Dr. Graber’s memoir, and the plates which accompany it, the large trachea of the leg in the Orthoptera is con- siderably swollen in the tibia, and sends off, shortly after entering the tibia, a branch which, after running for some time parallel to the principal trunk, joins it again. See, for instance, in his monograph, plate ii., fig. 43; plate vi., fig. 69 ; plate vii. fig. 77; &c. Now, I have observed that in many other insects the trachez of the tibia are dilated, and in several I have been able to detect a recurrent branch. The same is also the case in some mites. I will, however, reserve what I have to say on this subject, with reference to other insects, for another occasion, and will at present confine myself to the ants. If we examine the tibia, say of Lasius flavus, Fig. 9, we shall see that the trachea presents a remarkable arrangement, which at once reminds us of that which occurs in Gryllus and other Orthoptera. In the femur it has a diameter of about 52), of an inch; as soon, however, as it enters the tibia, it swells to a diameter of about 51, of an inch, then contracts again to 515, and then again, at the apical extremity of the tibia, once more expands to s4;. Moreover, as in Gryllus, so also in Formica, a small branch rises from the upper sac, runs almost THE TIBIA OF ANTS. 233 straight down the tibia, and falls again into the main trachea just above the lower sac. The remarkable sacs (Fig. 9,88) at the two ex- tremities of the trachea in the tibia may also be well seen in other transparent species, such, for instance, as Myrmica ruginodis and Pheidole megacephala. At the place where the upper tracheal sac con- tracts (Fig. 9), there is, moreover, a conical striated organ (x), which is situated at the back of the leg, just at the apical end of the upper tracheal sac. The broad base lies against the external wall of the leg, and the fibres converge inwards. In some cases I thought I could perceive indications of bright rods, but I was never able to make them out very clearly. This also reminds us of a curious structure which is found in the tibie of Locustide, between the trachea, the nerve, and the outer wall, and which is well shown in some of Dr. Graber’s figures. On the whole, then, though the subject is still involved in doubt, I am disposed to think that ants perceive sounds which we cannot hear The Sense of Smell. I have also made a numter of experiments on the power of smell possessed by ants. I dipped camel’s-hair brushes into peppermint-water, essence of cloves, laven- der-water, and other strong scents, and suspended them 17 234 THE SENSE OF SMELL. about } of an inch above the strips of paper along which the ants were passing, in the experiments above recorded. Under these circumstances, while some of the ants passed on without taking any notice, others stopped when they came close to the pencil, and, evidently perceiving the smell, turned back. Soon, however, they returned and passed the scented pencil. After doing this two or three times, they generally took no further notice of the scent. This experiment left no doubt on my mind; still, to make the matter even more clear, I experi- mented with ants placed on an isolated strip of paper. Over the paper, and at such a distance as almost, but not quite, to touch any ant which passed under it, I again suspended a camel’s-hair brush, dipped in assa- fostida, lavender-water, peppermint-water, essence of cloves, and other scents. In this experiment the results were very marked ; and no one who watched the behaviour of the ants under these circumstances could have the slightest doubt as to their power of smell. I then took a large female of F. ligniperda and tethered her on a board by a thread as before. When she was quite quiet I tried her with the tuning-forks ; but they did not disturb her in the least. I then ap- proached the feather of a pen very quietly, so as almost to touch first one and then the other of the antenne, which, however, did not move. I then dipped the pen in essence of musk and did the same; the antenna was slowly retracted and drawn quite back. I then THE SENSE OF SMELL. 235 repeated the same with the other antenna. If I touched the antenna, the ant started away, apparently smarting. I repeated the same with essence of laven- der, and with a second ant. The result was the same. Many of my other experiments—for instance, some of those recorded in the next chapter—point to the same conclusion ; and, in fact, there can be no doubt whatever that in ants the sense of smell is highly developed. CHAPTER IX. GENERAL INTELLIGENCE, AND POWER OF FINDING THEIR WAY. A NUMBER of interesting anecdotes are on record as tw the ingenuity displayed by ants under certain circum- stances. M. Lund, for instance, tells the following story as bearing on the intelligence of ants : '— ‘Passant un jour prés d’un arbre presque isolé, je fus surpris d’entendre, par un temps calme, des feuilles qui tombaient comme de la pluie. Ce qui augmenta mon étonnement, c’est que les feuilles détachées avaient leur couleur naturelle, et que l’arbre semblait jouir de toute sa vigueur. Je m’approchai pour trouver l’expli- cation de ce phénoméne, et je vis qu’d peu prés sur chaque pétiole était postée une fourmi qui travaillait de toute sa force; le pétiole était bientét coupé et la feuille tombait par terre. Une autre scéne se passait au pied de J’arbre: la terre était couverte de fourmis occupées & découper les feuilles 4 mesure qu’elles tom- baient, et les morceaux étaient sur le champ transportés dans le nid. En moins d’une heure le grand cuvre 4 Ann, des Sei. Nat, 1831, p. 112. ECONOMY OF LABOUR. 232 saccomplit sous mes yeux, et l’arbre resta entiérement dépouillé.’ Butes' gives an apparently similar, but really very different account. ‘The Saiiba ants,’ he says, ‘ mount the tree in multitudes, the individuals being all worker-minors. Each one places itself on the surface of a leaf, and cuts with its sharp scissor-like jaws a nearly semivircular incision on the upper side; it then takes the edge between its jaws, and by a sharp jerk detaches the piece. Sometimes they let the leaf drop to the ground, where a little heapaccumulates, until carried off by another relay of workers; but, generally, each marches off with the piece it has operated upon.’ Dr. Kerner recounts? the following story communi- cated to him by Dr. Gredler of Botzen :— ‘One of his colleagues at Innsbriick, says that gentleman, had for months been in the habit of sprink- ling pounded sugar on the sill of his window, for a train of ants, which passed in constant procession from the garden to the window. One day, he took it into his head to put the pounded sugar into a_ vessel, which he fastened with a string to the transom of the window; and, in order that his long-petted insects might have information of the supply suspended above, a number of the same set of ants were placed with the sugar in the vessel. These busy creatures forthwith ' Naturalist on the Amazons, vol. i. p. 26. 2 Flowers and their Unbidden Guests, Dr. A. Kerner. Trans. by W. Ogle, 1878, p. 21. 238 STATEMENT BY seized on the particles of sugar, and soon discovering the only way open to them, viz. up the string, over the transom and down the window-frame, rejoined their fellows on the sill, whence they could resume the old route down the steep wall into the garden. Before long the route over the new track from the sill to the sugar, by the window-frame, transom, and string was completely established; and so passed a day or two without anything new. Then one morning it was noticed that the ants were stopping at their old place, that is, the window-sill, and getting sugar there. Not a single individual any longer traversed the path that led thence to the sugar above. This was not because the store above had been exhausted; but because some dozen little fellows were working away vigorously and incessantly up aloft in the vessel, dragging the sugar crumbs to its edge, and throwing them down to their comrades below on the sill, a sill which with their limited range of vision they could not possibly see!” Leuckart also made a similar experiment. Round a wee which was frequented by ants, he spread a band soaked in tobacco water. The ants above the band after awhile let themselves drop to the ground, but the ascending ants were long baffled. At length he saw them coming back, each with a pellet of earth in its mouth, and thus they constructed a road for them- selves, over which they streamed up the tree. PREVIOUS OBSERVERS, 239 Dr. Biichner records the following instance on the authority of a friend (M. Theuerkauf) :— ‘A maple tree standing on the ground of the manufacturer, Vollbaum, of Elbing (now of Dantzic) swarmed with aphides and ants. In order to check the mischief, the proprietor smeared about a foot width of the ground round the tree with tar. The first ants who wanted to cross naturally stuck fast. But what did the next? They turned back to the tree and carried down aphides, which they stuck down on the tar one after another until they had made a bridge, over which they could cross the tar-ring without danger. The above-named merchant, Vollbaum, is the guarantor of this story, which I received from his own mouth on the very spot whereat it occurred,’! In this case I confess I have my doubts as to the interpretation of the fact. Is it not possible that as the ants descended the tree, carrying the aphides, the latter naturally stuck to the tar, and would certainly be left there. In the same way I have seen hundreds of bits of earth deposited on the honey with which I fed my ants. On one occasion Belt observed? a community of leaf-cutting ants (Hcodoma), which was in the process of moving from one nest to another. ‘ Between the old burrows and the new one was a steep slope. In- stead of descending this with their burdens, they cast 1 Mind in Animals, by Prof. Ludwig Biichner, p, i120. 2 Naturalist in Nicaragua, O. Belt, p. 76. 240 EXPERIMENTS AS TO POWERS. them down on the top of the slope, whence they rolled to the bottom, where another relay of labourers picked them up and carried them to the new burrow. It was arausing to watch the ants hurrying out with bundles of food, dropping them over the slope, and rushing back immediately for more.’ With reference to these interesting statements, I tried the following experiment :— October 15 (see Fig. 10).—At a distance of 10 inches from the door of a nest of Lasius niger I fixed Fig 10. an upright ash wand 3 feet 6 inches high (a), and from the top of it 3 I suspended a second, rather shorter wand (b). To the lower end of this @ second wand, which hung just over the ¢ entrance to the nest (c), I fastened a flat glass cell (d)in which I placed a number of larve, and to them I put three or four specimens of L. niger. The drop from the glass cell to the upper part of the frame was only 4 an inch; still, though the ants reached over and showed a great anxiety to take this short cut home, they none of them faced the leap, but all went round by the sticks, a distance of nearly 7 feet. A‘ ¢ P.M. there were over 550 larve in the glass cell, and I reduced its distance from the upper surface of the nest to about 2 of an inch, so that the ants could even touch the glass with their antenna, but could not reach up nor step down. Still, though the drop was so small, they all went round. At 11 P.M. the OF ECONOMISING LABOUR 241 greater number of the larvae had been carried off; so I put a fresh lot in the cell. The ants were busily at work. At 3 4.M.I visited them again. They were still carrying off the larve, and all going round. At 6 a.M. the larvee were all removed. I put a fresh lot, and up to 9 a.M. they went on as before. The following day (October 17) I took two longer sticks, each 6 feet 6 inches in length, and arranged them in a similar manner, only horizontally instead of vertically. J also placed fine earth under the glass supporting the larve. At 8 o’clock I placed an ant on the larve; she took one, and I then coaxed her home along the sticks. She deposited her larva and im- mediately came out again, not,- however, going along the stick, but under the larva, vainly reaching up and endeavouring to reach the glass. At 8.30 I put her on the larve again, and as she evidently did not know her way home, but kept stretching herself down and trying to reach the earth under the glass cell, I again coaxed her home along the sticks. At 9.3 she came out again, and again went under the larva and wandered about there. At 101 put her on the larve and again helped her home. At 10.15 she came out again, and this time went to the stick, but still wanted some guidance. At 10.45 she again reached the frame, but immediately came out again, and J once more coaxed her round. After wandering about some time with a larva in her mouth, she dropped down at 11.14. After depositing her larva, she came out directly and went 242 WANT OF INGENUITY IN ASSISTING under the larve. I again coaxed her round, and thie time also she dropped off the glass with her larva. At 12.30 she came out again, and for the last time I helped her round. After this she found her way by herself. At 12.20 another (No. 2) found her way round and returned at 12.37. For the next hour thei times were as follows :— No. 1. No. 2. 12.46 12.47 12.54 12.54 10 1.1 1.7 1. 8 1.12 1.14 1.19 1.21 1.26 1.28 1.32 1.34 1.38 1.41 1.45 1.47 1.52 1.54 Thus they both made 9 visits in an hour. As regards actual pace, I found they both did about 6 feet ONE ANOTHER OVER CHASMS, 243 ina minute. Soon after these began, other auts came with them. It was a beautiful day, and all my ants were unusually active. At 1 p.m. I counted 10 on the sticks at once, by 1.30 over 30, and at 5 in the after- noon over 60. They went on working very hard, and forming a continuous stream till I went to bed at 11; and at 4 in the morning I found them still at work; but though they were very anxious and, especially at first, tried very hard to save themselves the trouble of going round, they did not think of jumping down, nor did they throw the larve over the edge. Moreover, as I had placed some sifted mould under the glass, a minute’s labour would have been sufficient to heap up one or two particles, and thus make a little mound which would have enabled them to get up and down without going round. A mound } inch high would have been sufficient; but it did not occur te them to form one. The following morning (October 18) I put out some larvee again at 6 aM. Some of the ants soon came; and the same scene continued till 11.30 4.m., when I left off observing. Again, on October 22, I placed a few larve in a glass, which I kept continually replenished, which was suspended } of an inch above the surface of the frame containing their nest, but only connected with it by tapes five feet long, I then, at 6.30, put a L. niger to the larve; she took one and tried hard to reach down, but could not do so, and would not jump; so I 244 WANT OF INGENUITY IN coaxed her round the tapes. She went into the nest, deposited her larva, and immediately came out again. I put her back on the larvee at 7.15; she took one, and again tried hard, but ineffectually, to reach down. I therefore again coaxed her round. She went into the nest, deposited her larva, and came out again directly as before. I put her back on the larve at 7.35, when the same thing happened again. She got back to the nest at 7.40, and immediately came out again. This time she found her way round the string, with some help from me, and reached the larve at 7.50. I helped her home for the last time. The next journey she found her way without assistance, and reached the larve at 8.26. After this she returned as follows, viz. :— At 8.50 9. 0 9.10 9.17 9.28 T now made the length of the journey round the tapes 10 feet. This puzzled her a little at first. She returned as follows :— 9.41 10.35 9.55 10.44 10. 8 10.54 10.16 11. 6 10.26 11.14 with afriend CONSTRUCTING BRIDGES. 245 I now increased the length to 16 feet, and watched her while she made thirty journeys backwards and forwards. She also brought during the time seven friends with her. It surprised me very much that she preferred to go so far round rather than to face so short a drop. In illustration of the same curious fact, I several times put specimens of LZ. niger on slips of glass raised only one-third of an inch from the surface of the nest. They remained sometimes three or four hours running about on the glass, and at last seemed to drop off accidentally. Myrmica ruginodis has the same feeling. One morning, for instance, I placed one in an isolated position, but so that she could escape by dropping one- third of an inch. Nevertheless at the same hour on the followiag morning she was still in captivity, having remained out twenty-four hours rather than Jet herself down this little distance. Again I filled a saucer (woodcut, Fig. 11, s) with water and put in it a block of wood (w), on the top of which I fastened a projecting wooden rod (B), on the end of which I placed a shallow glass cell (4) containing several hundred larve. From this cell I allowed a slip of paper (P) to hang down to within 3; of an inch of the upper surface of the nest. At one side I put another block of wood (c) with a lateral projection (Dp) which hung over the cell containing the larve. I then made a connexion between D and A, so that ants 246 WANT OF INGENUITY could ascend c, and, passing over p, descend upon the larve. I then put some specimens of Lasius niger to the larve, and soon a large number of ants were en- gaged in carrying off the larve. When this had con- tinued for about three hours, I raised D 58; of an inck above 4. The ants kept on coming and tried hard to reach down from D to A, which was only just out of their reach. Two or three, in leaning over, lost their foothold and dropped into the larve; but this was obviously an accident; and after a while they all gave up their efforts, and went away, losing their prize, in spite of most earnest efforts, rather than drop ;3 of an inch. At the moment when the separation was made there were fifteen ants on the larve. These could, of course, have returned if one had stood still and allowed the others to get on its back. This, however, did not occur to them ; nor did they think of letting themselves drop from the bottom of the paper on to the nest. Two or three, indeed, fell down, I have no doubt, by accident ; but the remainder wandered about, until at length most of them got into the water. After a time the others abandoned altogether as hopeless the attempt to get at the larve. I waited about six hours, and then again placed the IN CONSTRUCTING BRIDGES, 247 glass (a) containing the larve so as to touch the piece of wood (D), and again put some ants to the larve. Soon a regular string of ants was established; when I again raised the wood (D) 5, of an inch above the glass (4), exactly the same result occurred. The ants bent over and made every effort to reach the larve, but did not drop themselves down, and after a while again abandoned all hope of getting the larve. In order to test their intelligence, it has always seemed to me that there was no better way than to ascertain some object which they would clearly desire, and then to interpose some obstacle which a little ingenuity would enable them to overcome. Following up, then, the preceding observations, I placed some larve in a cup which I put on a slip of glass surrounded by water, but accessible to the ants by one pathway in which was a bridge consisting of a strip of paper 3 inch long and 3 inch wide. Having then put a Lasius niger from one of my nests to these larve, she began carrying them off, and by degrees a number of friends came to help her. I then, when about twenty-five ants were so engaged, moved the little paper bridge slightly, so as to leave a chasm, just so wide that the ants could not reach across. They came and tried hard to do so; but it did not occur to them to push the paper bridge, though the distance was only about 3 inch, and they might easily have done so. After trying for about a quarter of an hour, they gave up the attempt and re- turned home. This I repeated several times 248 WANT OF INGENUITY Then, thinking that paper was a substance to which they were not accustomed, I tried the same with a bit of straw 1 inch long and } inch wide. The result was the same. I repeated this more than once. Again I suspended some honey over a nest of Lasius flavus at a height of about 4 an inch, and accessible only by a paper bridge more than 10 feet long. Under the glass I then placed a small heap of earth. The ants soon swarmed over the earth on to the glass, and began feeding on the honey. I then removed a little of the earth, so that there was an interval of about 4 of an inch between the glass and the earth; but, though the distance was so small, they would not jump down, but preferred to go round by the long bridge. They tried in vain to stretch up from the earth to the glass, which, however, was just out of their reach, though they could touch it with their antenne ; but it did not occur to them to heap the earth up a little, though if they had moved only half a dozen particles of earth they would have secured for them- selves direct acvess to the food. This, however, never occurred to them. At length they gave up all attempts to reach up to the glass, and went round by the paper bridge. I left the arrangement for several weeks, but they continued to go round by the long paper bridge. Again I varied the experiment as follows :—Having 1eft a nest without food for a short time, I placed some honey on a small wooden brick surrounded by a little moat of glycerine $an inch wide and about A, of IN CONSTRUCTING EARTHWORKS, 24S an inch in depth. Over this moat I then placed a paper bridge, one end of which rested on some fine mould. I then put an ant to the honey, and soon a little crowd was collected round it. I then removed the paper bridge; the ants could not cross the glycerine ; they came to the edge and walked round and round, but were unable to get across, nor did it occur to them to make a bridge or bank across the glycerine with the mould which I had placed so conveniently for them. I was the more surprised at this on account of the ingenuity with which they avail themselves of earth for constructing their nests. For instance, wishing, if possible, to avoid the trouble of frequently moistening the earth in my nests, I supplied one of my communities of Lasius flavus with a frame containing, instead of earth, a piece of linen, one portion of which projected beyond the frame and was immersed in water. The linen then sucked up the water by capillary attraction, and thus the air in the frame was kept moist. The ants approved of this arrangement, and took up their quarters in the frame. To minimize evaporation I usually closed the frames all round, leaving only one or two small openings for the ants, but in this case I left the outer side of the frame open. The ants, however did not like being thus exposed ; they therefore brought earth from some little distance, and built up a regular wall along the open side, blocking up the space between the upper and lower plates of glass, and leaving only one or two small openings for themselves. This struck 18 250 INGENUITY IN BUILDING NESTS. me as very ingenious. The same expedient was, mores over, repeated under similar circumstances by the tlaye: belonging to my nest of Polyergus. The facility or difficulty with which ants find their way, while it partly falls within the section of the subject dealing with their organs of sense, is also closely connected with the question of their general intelligence. Partly, then, in order to test how far they are guided by sight, partly to test their intelligence, J made various observations and experiments, the ac- companying woodcuts being reduced copies of tracings of some of the routes followed by the ants during the course of the observations. I may here note that the diagrams Figs. 12-17 are careful reductions of large tracings made during the experiments. Though not absolutely correct in every minute detail of contour, they are exact for all practical purposes. As the ants pursued their way, pencil-mark- ings in certain instances, and coloured lines in others, were made so as to follow consecutively the paths pursued. Experiment 1.—February. On a table communi- cating with one of my nests (see Fig. 12)I placed upright a common cylindrical lead pencil } inch in diameter and 7 inches long, fastened with sealing-wax to a penny piece. Close to the base of the pencil (a) I brought the end of a paper bridge (B) leading to the nest, and then placed a shallow glass with larve® at c, DIFFICULTY IN FINDING WAY. 251 4 inches from the base of the pencil. I then put au ant to the larve; when she had become acquainted with the road, she went very straight, as is shown in the woodcut ‘Fig. 12). In one case, at the pvint E, she dropped her larva and returned for another. When Fig. 12. Routes followed in experiment No. 1, as detailed above. A, position of pencil. 8, paper bridge. c and D, glass with larva, £, point where larva dropped, the opposite arrow and loop marking return route, 1,2, 3, 4, comparatively straight paths to the glass, 6, 6, circuitous route on shifting of glass. , different access to nest, she returned on the next journey and was on the glass, I moved it 3 inches, to D, so that the end of the glass was 6 inches from the base of the pencil. If she were much guided by sight, then she would have had little 252 DIFFICULTY IN or no difficulty in finding her way back. Her pathway, however (No. 5), which is traced on the paper, shows that she was completely abroad ; and, after all, she got back to the nest by a different route. Fig. 13. See Routes followed in experiment No. 2, as mentioned in text B, paper bridge leading to nest. ©, glass tray with larve, ia its first position ; and D in its position when shifted, 1, 2, 3, 4, thin white lines indicating the comparatively straight routes, 6, thick white line, and 6, dotted” ne showing tortuous paths when glass had peen altered in position The arrows indicate directions travelled, FINDING THEIR WAY. 253 I then varied the experiment as subjoined, and as shown in the woodcut (Fig. 13). Experiment 2.—I connected the table with the nest by a paper bridge, the end of which is shown at B (Fig. 13), and which came down about an inc from the pole supporting the nest (see Fig. 1). Th’ pole rose 18 inches above the table. I then put t's glass tray (C) with larve as before, 12 inches from the base of the pole, and put an ant to the larve. When she had learnt her way I traced four of her routes, as shown in the thin lines 1, 2,3,4. I then on her next journey (5, thick white “ae), when she was on the tray (C), moved it three inches to D, as shown in the figure, and again traced .er route. The contrast is very striking between the : latively straight thin white lines 1, 2, 3, 4 of the for ¢ journeys when familiar with the road; whereas in th: broad white line No. 5 the zigzag twistings show how much difficulty the ant experienced in finding her way. When she re- turned I again moved the tray as before, and the dotted sinuous white line (6) shows the course she followed. Experiment 3.—I then again varied the experi- ment as follows :—I placed the larvae in a small china cup on the top of the pencil, which thus formed a column 74 inches high. The cross line close to the arrows (Fig. 14) is as before, the base of the paper bridge leading to the nest. c shows the position of the penny on which the pencil was supported. The dotted white lines 1, 2, 3,4 show the routes of a marked ant on four 254 SIGHT LITTLE USED successive journeys from the nest to the base of the pencil. Ithen moved the pencil 6 inches to D, and the two following routes are marked 5 and 6. In one of them, 5 (thick white line), the ant found a stray Fig. 14 Routes followed in experiment No, 3, as described in text The line at the six arrows represents a paper bridge going to nest c, china cup on top of pencil. D, pencil moved. 4, place where a stray larva was found. 1, 2, 3, 4, dotted lines show the nearly direct journeys. 5, thick white line (crossing ¢ in black) of route returning to nest, the ant having picked up a stray larva at EB. 6& very circuitous thin white line of track from nest to pencil p. IN FINDING THEIR WAY 255 .arva at E, with which she returned to the nest, without finding the pencil at all. On the following journey, shown in the fine white zigzag line (6), she found the pencil at last, but, as will be seen, only after many meanderings. Diagram of complex path traversed in experiment 4. A, first position of pencil. B, second position of pencil. 1,2 straight lines of two tracks of the observed ants. 3, winding narrow white line, showing course pursued by the same ant before arriving at B, when the position of the pencil was unchanged. Experiment 4.—I then repeated the observation 256 SIGHT LITTLE USED on three other ants (see Figs. 15-17) with the same result: the second was 7 minutes before she found the pencil, and at last seemed to do so accidentally; the third actually wandered about for no less than half an hour (Fig. 15), returning up the paper bridge several times. Other experiments somewhat similar to the pre- Fig. 16. Diagram representing three tracks of an ant in another experiment A, the first position of pencil and the food, towards which and from the base-line of nest 1 and 2 lead by nearly direct broadish white lines to A. When the latter was removed to B the ant, in its effort to reach this, pursued the narrow white winding line ending in3—7> ceding, the results of which. are shown in the figures 16 and 17, seem to prove that this species of ant, at any IN FINDING THEIR WAY. 257 rate, guides itself but little by sight. This, which 1 had not at all anticipated, seems to follow from the fact that after the pencil and tray of larve had been removed but a short distance to the right or left, the Fig. 17, Another tracing showing a similar experiment. 1, 2, 3, the direct broad lines towards A; and 4, the complicated track made whep reservoir of larve was removed to B. ants on their journey to the shifted object travelled very often backwards and forwards and around the spot where the coveted object first stood. Then they would retrace their steps towards the nest, wander hither and 258 IMPORTANCE OF SCENT. thither from side to side between the nest and the point A, and only after very repeated efforts around the original site of the larve reach, as it were accidentally, the object desired at B. Another evidence of this consists in the fact that if when ants (L. niger) were carrying off larve placed in a cup ona piece of board, I turned the board round so that the side which had been turned towards the nest was away from it, and vice versa, the ants always returned over the same track on the board, and, in consequence, directly away from home. If I moved the board to the other side of my artificial nest, the result wasthe same. Evidently they followed the road, not the direction. In order further to test how far ants are guided by sight and how much by scent, I tried the following ex- periment with Lastus niger. Some food was put out at the point a on a board measuring 20 inches by 12 (Fig. Fig. 18. 18), and so arranged on that the ants in going lle straight to it from the ri nest would reach the nl board at the point b, : : and after passing under LI a paper tunnel, c, would a proceed between five pairs of wooden bricks, each 3 inches in length and 14 in height. When they got to know their way, they went quite straight along the line d eto a. The board was IMPORTANCE OF SCENT. 259 then twisted as shown in Fig. 19. The bricks and tunnel being also rearranged so that they were exactly in the same direction as before, but the board having been moved, the line d e was now outside them. This change, however, did not at all discom- Fig. 19. pose the ants; but instead of going, as before, through the tunnel and between the rows of bricks to a, they walked exactly along the old path to e. I then arranged matters as before, but without the tunnel and with only three pairs of bricks (Fig. 20). When an ant had got quite used to the path d to e,I altered Fig. 20. the position of the 3 bricks and food, as a} shown in Fig. 21, mak- l I ing a difference of 8 inches in the position H of the latter. The ant I: H came as before, walked =a J] a up to the first brick, touched it with her antenne, but then followed ner old line toa. From there she veered towards the food, and very soon found it. When she was gone, I altered it 260 THE SENSE OF DIRECTION. again, as shown in Fig. 22; she returned after the usual interyal, and went again straight to a ; then, after some Fig. 21. wanderings, to f, and r at length, but only after a lapse of 25 0 minutes, found the 4 food at g. These ex- 4 4 periments were re- Y peated more than once, @ and always with simi- Fig. 22. jar results. I then varied matters by re- 3 A ° 2 Z Aa DIVISION OF LABOUR. 325 cm on oooscocsoo wy Szeoccos cosce oF of oO ° ecoooseo ecscooscoosoo of oof Ag A 4 Lom 2 -_ ooo io jocooo eosooscosesce o isyo . . . © eeoose tcooscocso co io tcoocco Sogec ii eoosecooooesocoosososocoososoos Cio 1° of . . . LOS O22 292255 S2Se2) poooeoco 0:9 19 oO or) . . PRESSES SSS SVS Sa Say SS soooo co :0 ty; a Ot oO . . . . . So iggoe iesosoocss jseco io i o icos a . . 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Jan, & a Zeeccoe ecooooooo oo ooSo OO © a |ooooooso ecoo,ooosoocs oo « weecooe ecocoscoscoscooso So er lo ticoceooo C9000 19:09 :090 Of oO ej} ocoooos So, oooooooSso oo ~ en a ee oo © w [ooo oescoo coos oSoZ SoSooS OO «a |"coccce cooco ft scococe to of a a : a .o Be © a |O igzgooo SOS Coo o, Sooo SO Ke a |ooooooso scoscoesceoscosceosesso Sco oem a . ¢ . eo :cooc ORF coo ico a : Paz wiZ : coco coo 7 & : a |eoooo io oo,eoce loooogo oo Ln] Z| Beeoosee cosooccoscoococe co . of 16 o 8 of a Co;yoco Cncoeoo,ccoooce of om eo - © 300 00 a |oo CSS SOLOoLFOCSO 2 zz wez SRS Eee, oO © Ow se |ooooco oosyeco % qi weRZeCCSSO OO = . . ° . ‘3 105 10009 09 $00 :o0c0CcCO 3 Coo = OPSCaNTH 10 : Saoeaee aaa ARARSR RB DIVISION OF LABOUR. eococeoecooocosoeocseooso soo 327 fo) oon ao SST irre ee ee we eee ooo Oo foo) Ser seoom Soe oeeoS cece ooo a 3 © . iid seooooowmoooooso COP so Poco ec OCC OFoco? coco a AG a a ao weooo Soo 6 a a ad ooo qoooooocoocececoeceo |: oooo oco 3 a 2 = ie o feeding 7.0 . oo iow, soooooooooeoooooosooso qoooococoooocoooooooococoooooosoo eoooocooeocoocooocoooooescoeseo“e3o ecocoococoeosoooooooso -coocSooS = . oo SSSeee sree coe. Sse PINS S'S, Friend, marked 0 lher N 9 oO . OS eS SS SS SS SONOS soococe 0 eoocoocooeoccoosescoo Sao @eooocoovcvocrrtrzrsooecooooooscesoceofo coopoocsssoecoooooccosse : eco tooo eo SoSoSoOS IS PISO HO :S6 5 DROMAMDHBONOROGWN sw ear eeice se ums te pn a as ae nS 23 a fm 328 Taste II.—Slaves of Polyergus. (See p. 45.) DIVISION OF LABOOR. a I oe ocooco ° ° ue eSiee” Ha 36 — a) aw : : ; iy, Zz? : @ cr o 1O CS so00°0 a) a . one, © > coos? SC socco off i a q one, A wo ~o es |oo 7 ieee Sooo CCSS iposs Ss cooot eB occ ccoc ooo toe 0 aq Z2AZ a «w | 2r 8 reBoot cof s-focootoce 4SZ'‘ BZ°* Ge a A”~ 2 A er oe 108 1B ccooe fm occ occoo ” 7 ‘: ; a “TAG az 6 © . Oe co Boot Be cocococ oot coe 3 . a A'Aa a Ss ae poe ee Cole Toooots io “lam & Zz Zee a : as 19 5 f aloo poocossoooo, iooooce io 10 aw 1 wo © a on, SNE See re ee oo Saco. oS isos ooo LK oSoe ao ZZ A4~Z a E Cd oo - oo! ovoccoot of coot tos Ze? wyAZrZ Aaa Az ot 2 Ww _ goo ss oO. 9 Opr,ooooocooo oo o 7 1OoO :o oe 2, Eat oe Ze o-7 AF HCO-MDARHOCANHMHAOOrMOHAS = a aN ANANANANANANANSH 2 ae - bp 3 A ° 2 %, Aa DIVISION OF LABOUR. © 10 wIooeooooy, o eoococooooCoSO 5 © ococoococoodg cooscoeosooooco So io tocoocS BP scoff ocoocoo Pe a Az oO 3B OOo 1900008 Cf icocooocooooS a ote? Soocop cooPpocoooOoOL o,o°o a A wow wy 1 oo, cccooco, eiticopfooocsoo: a mm a . aw Xo © coococoocod oooooeooo ooo: =H Zi . wo = . oooo S22 SO SSS SSCS Oe 22 2 2 . 06 . oooooo ISS OS eS See : eoooop occas es eoooo,coooo: ooooco N5{/N5 ecoscocoof oo, tBooe A Zz iz . oO © oooocooocooooeoeoeeo 1S SOROS OSS co © 1 ooooo,coco C2229 gl CeS2 a A SecococCCOPcoop Poof osccoo gS a AZ A a 20000 Hooo fe PB ooe PoP ocoog A~ Aa wr 4 2108 oooocooococoeoce|coan“a IBZ PO OOS © . ee 2 2 .- SL,e:criiiL~ocescoceo i: ‘coooe a A i VWI OM ARON NH WOOL DRS AAC wH AFAR HANANAAANAAH : q s 5 23 328 330 DIVISION OF LABOUR. i o sre o of 2%o0f coe = AA A %3 3 oO @ o E3000 COSTS O° = me A SoS Ge « o ecco oC ecoscOostD OS 6 cooo PF sooclt? of Z “Aa © oy 1O00 ~ e2cco2® co fons ‘ a A 4 ‘2 ° :o000 e SS66e° 66 So a AZ aj o S| “ o ticooo o coofoo of a a aA |e o ococo Oo eocosoo oO ° = s ° Ss a a seco o eeSsons ee s ~ 1a | ES coos So coco OO Evo ° o a — ex EZ — ot _ ico} oO 3 s o ot:00 >: eccooco sco ae = a aH a oo see o ec tesco oo ° S o ococo o ecoooo of ° ig o o nooo o8oceosceo oS = ei 33 oO o o o9oco o ec90c0co oo BET EEA ~ o oosco eo ce 2%o00 co > ZAG od > aY oa a 7 e if < x 2 SC ef fo ZG jcocey, io BE ao OR ° ra OI OD 2 ” During the whole day she brought no friend, and only one other ant found the honey, evidently an inde- pendent discovery. 348 POWER OF COMMUNICATION. APPENDIX D. Tue following are the details referred to on page 164 :— Septenrber 24, 1875.—I put out two sets of larve ; and to one of them I placed two specimens of Myrmica ruginodis, which I will call 1 and 2. They returned as follows, carrying off a larva on each journey :— No. 1. No. 2. 10.23 10.26 10.28 10.32 10.34 10.37 10.40 10.41 bringing a friend, 10.50 10.55 1l. 6 11.16 11.40 11.44 11.45 11.46 an ant came alone, 11.56 12. 0 12. 6 bringing a friend. 12.11 POWER OF COMMUNICATION. 349 No. 1. No. 2. 12.15 12.16 12.17 an ant came alone. 12.22 12.22 5 6 12.29 12.34 12.36 12.40 12.45 an ant found the second 12.47 set of larvee. 12.53 12.58 two ants found the 12.59 second set of larvae. 1 5 1. 6 1. 7 an ant found the second 1.16 set of larvee. 1.20 1.21 1.26 1.35 1,42 1.47 1.54 1.55 with 2 friends. 1.59 2. 2 2.3 an ant found the 2.4 larvee. 2. 9 with a friend. 2.10 2.16 2.18 2.24 2.25 2.25 another ant found the 2.34 second set, of larvee. 350 POWER OF COMMUNICATION. No. 1. 2.36 2.44 2.51 3. 1 3.10 3.18 3.28 3.40 3.48 3.55 4. 0 4. 8 4.16 4.27 4.35 4.42 4.53 No, 2. 2.41 2.45 2.50 2.55 3. 0 3. 6 3.10 3.17 3.22 3.27 3.36 3.47 3.53 3.59 4.7 4.14 4.20 4.31 4.39 4.42 4.47 4.53 with a friend, POWER OF COMMUNICATION, 351 No. 1. No. 2. 4.58 5. 3 5. 5 5. 9 5.17 5.17 5.25 5.32 5.40 5.46 5.55 6. 5 6. 8 6.11 6.16 6.20 They came no more up to 7.30, when we left off watching. The following morning at 6.5 I found No. 1 wandering about, and evidently on the look-out. I put her to some larve; and shortly afterwards No. 2 also found them. Their visits were as follows :— 6.10 6.21 6.36 6.42 6.44 6.52 7 1 7.1 NaN nN were CO bo bo om 7.30 another ant found the 7.30 larvee. 7.40 352 POWER OF COMMUNICATION. No. 1. No. 2. 7.49 7.54 8. 5 8.13 8.25 8.31 8.39 8.44 8.48 Thus, during this period these two ants carried off respectively 62 and 67 larve; 10 strangers found the larvee, half of them only coming to the set visited by the ants under observation. This seems to show that most of them, at any rate, found the larve for them- selves. I will now pass to Lasius niger. September 27, 1875.—At 3.55 p.m. I put an ant of this species to some larve. She returned as follows :— 4. 3 5. 5 4.11 5.10 4.21 5.14 4.25 5.18 4.28 5.23 4.31 5.29 4.37 5.40 4.40 5.43 4.44 5.46 4.48 5.50 4.52 5.54 4.56 5.59 5. 0 wheu she met with an accident. During this time no other ant came to the larve. On October 1, 1875, at 6.15 a.m., I put three speci- POWER OF COMMUNICATION 353 mens of Lasius niger to some larve. One did not return; the other two behaved as follows :— No, 1 returned to the larve at No. 2 at Other ants came at 6.52 7.12 7.14 to lot 2. 7.22 7.30 7.32 7.42 7.42 7.45 to lot 3. 7.50 7.54 8. 0 8. 1 8. 6 with a friend. 8. 6 8. 9 8.10 8.17 8.19 to lot 1. 8.23 yy 8.25 8.26 8.32 8.36 8.37 45 8.38 8.39 8.41 8.44 8.45 Here I left off watching for half an hour. 9.22 9.28 9.29 9.35 9.35 854 POWER OF COMMUNICATION, No, 1 returned to the larve at No. 2 at Other ants came at 9.41 9.45 9.47 : 9.50 9.52 9.54 with a friend. 9.57 9,58 to lot 1 10. 0 10. 1 10. 9 10.11 10.13 with a friend, _ 10.16 10.16 10.25 10.30 10.36 10.46 10.50 10.55 10.58 11. 0 11. 2 11. 3 11. 7 11. 8 11.15 11.16 11.19 11.19 11.23 . 11.25 11.27 11.29 with a friend. 11.30 11.33 11.35 POWER OF COMMUNICATION. 355 No. 1 returned to the larvee at No. 2 at Other ants came at 11.37 11.41 11.42 11.45 11.47 to lot 1. 11.48 11.49 11.53 11.59 12. 1 12. 4 12. 8 12. 9 12.11 12.14, 12.15 12.15 12.18 12.19 ,, 12.20 12.21 12.25 12.29 with a friend. 12.30 12.35 12.36 12.39 12.42 12.43 12.45 12.47 12.48 12.51 12.53 12.54 12.56 5 12.57 12.57 1. O with friend. 1.0 356 POWER OF COMMUNICATION, No. 1 returned to the larve at No. 2 at Other ants came st 1. 2 1. 5 Led 1. 9 1.10 1.11 to lot 1. 1.13 1.14 1.15 1.18 1.18 1.21 1.24 1.27 1.27 1.28 1.30 1.33 1.35 1.36 1.39 1.42 1.42 1.45 1.46 1.48 1.48 1.61 1.53 1.57 1.59 2:1 2.4 2.15 2.17 2.21 2.22 2.25 2.29 2.31 POWER OF COMMUNICATION, 35) No. ! returned to the larvez at No.2 at Other ants came ag 2.33 2.37 2.39 2.40 2.43 2.44 2.47 2.49 2.50 2.54 2.57 3. 0 3. 4 with a friend. 3. 6 3. 9 with a friend. 3.12 3.14 3.16 3.16 3.20 3.21 3.23 3.26 3.26 3.30 3.30 3.33 3.33 3.35 3.35 3.37 e 3.38 3.39 3.41 3.43 3.45 3.46 3.48 3.49 3.54 4. 0 358 POWER OF COMMUNICATION. No 1 returned to the larve at No.2at Other ents came at 4. 3 4.4 4. 7 4.12 4.15 4.20 4.26 4.29 4.31 4.32 4.34 4.36 4.39 4.40 4.42 4.43 4.44 4.45 4.49 4,49 4.55 4.56 4.58 4.59 5. 2 5. 2 5. 6 with two friends, 5. 7 after which she came no more. The first ant returned at 5.10 5.13 5.15 5.18 5.21 5.25 5.28 6.31 5.33 to lot 2. POWER OF COMMUNICATION. $56 The first ant returned at 5.35 7.28 5.38 7.31 5.41 7.34 5.45 7.38 5.51 7.41 5.54 7.44 6. 0 TAT 6. 4 7.51 6. 7 7.55 6.14 7.59 6.17 8. 2 6.20 8. 5 6.28 8.12 6.31 8.15 6.48 8.18 6.54 8.20 7. 0 8.24 7. 3 8.28 7. 6 8.32 711 8.35 7.14 8.38 7.18 8.42 7.21 8.44 another 7.24 8:45 [ant came. 7.25 9.44 We continued to watch till 10.15, but she came no more. She had, however, in the day carried off to the nest no less than 187 larve. She brought 5 friends with her; less than 20 other ants came to the larve. October 3.—I put a Lasius niger to some larva, Sbe returned as follows viz:— 1.42 1.48 1.52 2. 0 tb top be Or bo CO 12 with a stranger. 1 30 POWER OF COMMUNICATION. 2.19 4.7 2.24 4.10 2.27 4.12 2.32 4.15 2.36 4.18 2.40 4.22 2.44 4.25 2.49 4.29 2.57 4.32 3. 1 4.35 3. 4 4.38 3. 7 4.43 3.10 4.46 3.13 4.49 3.15 4.54 3.18 4.57 3.20 5. 0 3.23 5. 3 3.31 5. 6 3.35 5.10 3.38 5.14 3.41 5.18 3.49 with a friend. 5.22 3.51 5.26 3.54 5.29 3.57 She dropped on the floor 4,1 of my room. 4.4 [ picked her up; and she returned at 6.40 7. 7 with 3 friends. 6.50 7.11. She now fell into 6.54 some water. 7.4 In addition to the ahove experiments with larva, I tried the following with syrup. POWER OF COMMUNICATION. 361 April 19.—I put. out a little syrup on eleven slips of glass,which I placed on eleven inverted flower-pots on the lawn. At 8.35 a Lasius niger found the honey on one of the flower-pots. 8.50 | she returned to the honey, and at } 9. 5 went back to the nest. 9.21 3 is 9.30 si % 9.42 29 ” 9.50 ” 9 10.12 A i 10.21 - ~ 10.35 % ¥ 10.46 < 5 ll. 9 bs : 11.20 a * 11.45 ~ HA 11.50 i “a 11.57 : . 12. 2 :: a 12.20 a i 12.30 = a 12.45 ? = 12.53 s 5 1. 8 9 ” 1.18 ” ” 1.34 ” ” 1.43 ” »” 1.57 ” 2” 2. 7 ” ” 2.28 ” ” 2.33 yy ” 249 ‘i 2.68 % 4 2.59 ” ” 3. 2 ” ” 3. 9 ” ” 3.11 ” ” 3.29 ry) ” 3.30 ” ” 3.59 ) ” 4. 8 ” ” After which I watched till 6 p.m.; but she did not return again tothe honey. During the above time eight ants came to the same honey, and twenty-one to the other ten deposits. On July 11 I put one of my specimens of Lasius niger to some honey at 7.10. She fed till 7.25, when she returned to the nest. At 7.32 she returned. At 7.36 another ant came, TAT rr 7.50 [whom I imprisoned. 8. 0 a 8.11 2 7 8.18 : 25 36% POWER OF COMMUNICATION. At 8.36 she returned. 8.59 i" 9:17 . 9.38 és 9.53 ss 10.10 ie 10.27 . 10.44 55 1l. 6 11.16 - 11.38 12. 0 ‘ 12.36 - At 12.45 another ant came, [whom Iimprisoned. 12.56 % 1.21 ‘ 1.44 35 2.10 : 2.21 2.29 % 2.50 2.51 z 3. 5 a5 After this she did not come back any more up to 8 P.M. April 25 was a beautiful day. At 9 a.m. I put some syrup in the same way on five inverted flower-pots, and at 9.10 put an ant to one of the deposits of syrup. At 9.34 another ant came to the samesyrup. This one I willcall No 2. At 9.40 No. 1 returned. 10.45 No. 2 55 At 11 one came to the same honey; this one I will call No. 3. 11. 7 No.1 . but did not come back any more 12.31 No. 2 0 and at 12.47 went POWER OF COMMUNICATION. 363 1.15 No. 3 returned, and at 1.25 went. 1.22 No. 2 ss a 148 ,, 1.54 No. 3 3 35 BeB sy 2.18 No. 2 i a 2.30 ,, 2.35 No. 3 5 5 2.36 4, 2.56 No. 2 59 9 Se ws 3.24 No, 2 returned. 4.19 No.2 ,, After which I went on watching till 7, but none of these three returned. During the day 7 ants came to this honey, and 27 to the other four deposits. Here, therefore, it is evident that the three watched ants did not communicate, at any rate, any exact information to their friends. June 27, 1875.—I placed four inverted glasses (tumblers) on the grass, and on the top of each placed a little honey. I then, at 8 o’clock, put two ants, be- longing to F’. nigra, to the honey on one of the glasses. At 8.25 No. 1 came back, and at 8.45 she returned to the nest, but did not come to the honey any more. At 9.5 No, 2 came out and wandered about; I put her to the honey again; she fed and at 9.22 returned to the nest. she returned to the went back to the mt a:28 { honey, and at ae nest. 10.42 ea 10.50 if 10.58 ae 11.10 is 11.21 ot Sees 11.39 ee 12.45 - & 12.59 . 1.40 ” ” I continued to watch till 7 P.M., but neither of them teturned any more. August 7, 1875.—I put out four small deposits of honey (which I continually renewed) on slips of glass placed on square pieces of wood, and put an ant (LZ. niger) to one of them at 9.20. She fed and went away. 364 POWER OF COMMUNICATION. At 9.35 she returned, and fed till 9.43 10.14 - i" 10.17 10.25 i. ie 10.27 10.37 - . 10.40 This time a friend came with her. At 10.47 she returned, and fed till 10.53 11. 0 i : 11.14 11.35 i‘ i 11.40 11.52 3 ~ 11.55 12.13 : - 12.16 1. 0 ‘ i 1. 5 1.15 ee 1.18 1.26 - ‘ 1.29 1.45 B ie 1.48 1.58 . 2.1 2.9 - . 2.14 2.20 5 5 2.21 She was dix [turbed. 2.25 z as 2.30 2.37 i : 2.40 3. 2 ‘ 3. 8 3.16 ; f 3.20 3.39 Z i 3.41 3.58 - 4, 2 4.13 ce 4.20 4.29 : : 4.36 At this time there was a shower of rain, so I removed the honey for half an hour. At 5. 2 she returned, and fed till 5.10 5.20 “ <5 5.25 5.33 i 5.37 5.42 . : 5.45 5.50 : Z 5.52 5.58 ” ” 6. 6 6.15 . 6.18 6.21 4 ‘ 6.23 POWER OF COMMUNICATION. At 6.25 she returned, and fed till 6.27 6.32 3 6.35 6.40 . “ 6.44 6.49 i . 6.53 7.15 - : 7.20 7.25 ’ : 7.27 7.30 * . 7.33 7.36 7.37 ” 365 During the whole of this time only three other ants caine to the honey. On January 3, 1875, I placed some larve in three small porcelain saucers in a box 7 inches square attached to one of my frame-nests of Lasius flavus (Pl. I. Fig. 2). The saucers were in a row 6 inches from the en- ‘trance to the frame, and 14 inch apart from one another. A‘ 1.10 an ant came to the larve in the cup which I will call No. 1, took a larva, and returned to the nest. 1.24 she returned and took another. 1.45 » » 2.10 she went to the further saucer, No. 3. I took her up and put her to No. 1. She took a larva and returned. 2.24 she returned to cup No. 3. As there were only two larvee in this cup, I left her alone. She took one and returned. 2.31 she returned to cup No. 3 and took the last larva. 2.40 she came back to cup No. 3 and searched diligently, went away and wandered about for two minutes, then returned for another look, and at length at 2.50 went to cup No. 1 and took a larva. 3. O came to cup 1 and took a larva. 3. 7 >» ” 366 POWER OF COMMUNICATION 3.15 came to cup 1 and took a larva, first, however, going and examining cup 3 again. 3.18 came to cup 3, then went to cup 2 and took a larva. 3.30 came to cup 3, then went to cup 2 and took a larva. 3.43 came to cup 3, then went to cup 2 and took a larva. 5.53 came to cup 3, but did not climb up it, then went to cup 2 and took a larva, which she either dropped or handed over to another ant; for without returning to the nest, at 3.55 she returned to the empty cup, and then to cup 2, where she took the last larva, so that two cups are now empty. 4. 3she came to cup 3, then to cup 2, and lastly to cup 1, when she took a larva. 4.15 came to cup 1 and took a larva. 4.22 ” ” 4.38 ” ” 5. Ocame to cup 3, then to cup 2, and lastly to cup 1, when she took a larva. 5.19 came to cup 1 and took a larva. 5.50 5 2, and then to cup 1 and took a larva. 6.20 ss 1 and took the last larva. I now put ahout 80 larve into cup 3. It is remarkable that during all this time she never came straight to the cups, but took a roundabout and apparently irresolute course. At 7.4 she came to cup 1 and then to cup 3, and then home. There were at least a dozen ants exploring in the box; but she did not send any of them to the larvee. At 7.30 she returned to cup 3 and took a larva. POWLR OF COMMUNICATION, 36% I now left off watching for an hour. On my return at 8.30 she was just carrying off a larva. 8.40 she came back to cup 3 and took a larva. 8.55 she came to cup 1, then to cup 3 and took alarva. 9.12 ” ” ” ” 9.30 ” 3 % ” 9.52 ” ” ” ” 10.14 $s 1 oh ” 10.26 she went and examined cup 2, then to cup 3 and took a larva. At 10.45 she came to cup 3, and I went to bed. At 7 o’clock the next morning the larve were all removed. In watching this ant I was much struck by the difficulty she seemed to experience in finding her way. She wandered about at times most irresolutely, and, instead of coming straight across from the door of the frame to the cups, kept along the side of the box; so that in coming to cup 3 she went twice as far as she need have done. Again, it is remarkable that she should have kept on visiting the empty cups time after time. I watched for this ant carefully on the following day; but she did not come out at all. During the time she was under observation, from 1 till 10.45, though there were always ants roaming about, few climbed up the walls of the cup. Five found their way into the (empty) cup 1, and one only to cup 3. It is clear, therefore, that the ant under observation did not communicate her discovery of larvee to her friends. The following day I watched again, having, at 7 A.M., put larve into one of the porcelain cups arranged as before. No ants found them for several hours. At.11.37 one came and took a larva. », 11.50 she returned and took a larva. » 11.59 3 »5 12. 9 ” ” » 12.16 os im POWER OF COMMUNICATION. At 12.21 she returned and took a larva » 12.26 ” ” y 12.32 ” ” y) 12.37 ” ” ” 12.41 ” ” x 12.45 ” ” » 12.50 ” ” ” se ” ” ” : ” 9 » 1.11 ” ” 9 (1.21 ” ” » 1.35 »» »” » 1.40 0 » » (1.44 ” ” » 1.52 ” ” ” pas ” ” ” : ” 3” 99 2.10 ” ” 9-217 ” ” » 2.24 ” ” 9 2.30 ” ” » 2.36 ” ” » 2.43 ” ” » 2.48 » ” » 2.54 99 ” ” ne » » ” . ” ”» » 3.10 = ss » 3.14 ” ” » 3.19 » ” 9» 3.34 36 35 9 3.39 ry) ” » 3.47 » ” » 3.56 ” ” » 4.7 ” ” » 4.138 55 s » 4.20 Ss 4 CO-OPERATION 369 At 4.28 she returned and tuok a larva ” 4.39 ” ” » 4.44 0 » ” 4.50 bP ” 9 4.55 2 39 ” ; 9 ” ” ae ” ” » 5.17 > ” ” 5.23 2” 9 ” 5.28 ” ” ” 5.40 oP) 2 ” 5.45 ob) ” ” Sige 29 ” bb * 29 9 ” 6.13 ” 9 ”» 6.35 ” 9 7 9 6.40 2”? ” 9 6.46 oP > ” 6.51 ” be) be) 6.58 ” ” ” 7. 2 ” 93 ” 7. 8 ” 9° 39 7.12 bE ? ” 7.16 9 ” » 7.21 03 » ” 7.26 9 39 DY 7.39 5 9? 9 7.44 2” 9 %” 7.53 ” 9 » 7.57 > 9 ” . ” ” 29 2 ” » » 8.13 ” ” » 8.20 ” ” » 8.26 3 ” » 8.31 ” » » 8.38 » » 370 EXPERIMENTS ON CO-OPERATION. At 8.45 she returned and took a larva. » 8.50 » » ” 8.55 ” ” ” 9. 2 ” 9 ” 9.11 39 » Ee) 9. 1 9 ” ”? ” 9.25 29 ” ” 9.33 ” ” 0 9.40 ” ” » 9.46 » » ” 9.52 ” 9 » 10.32 » » 3 10.39 29 ” Pd 10.49 29 3 ” 10.54 ” 2 9 1 1. 1 oe 39 At this time I went. to bed. There were still about twenty-five larve in the cup, which had all been removed when I looked at 6.15 the next morning During the whole time she was under observation, only two other ants found their way to the cup, though there were some wandering about in the box all day. Towards evening, however, they went into the nest, and for some hours my ant was the only one out. It will be observed that she returned at shorter intervals than the previous ones. This was partly because she had a shorter distance to go, and partly because she was not bewildered by three cups, like the preceding. I had plae2d a bit of wood to facilitate her ascent into the cup. This she made use of, but instead of going the shortest way to the cup, she followed the side of the box, partly, perhaps, because the floor was covered with a plate of porcelain. This, however, would not account for the fact that at first she invariably went beyond the cup, and even past the second cup; gradually, however, this circuit became smaller and smaller; but to the EXPERIMENTS ON CO-OPERATION. 371 tast she went round the outside of cup 1, instead of going straight to the spot where I had placed the bit of wood. On January 9 again I watched her under simi lar circumstances. From 9.35 to 1.40 she made 55 journeys to and fro, carrying off a larva each time; but during this period only one other ant found the larve. In the afternoon of the same day I watched the ant which had been under observation on the 3rd Jan. From 3.27 to 9.30 she made forty-two visits, during which time only four other ants came to the larva. On January 10 I watched the same ant as on the 4th. Between 11 a.M. and 10 P.M. she made no less than ninety-two visits; and during the whole time only one strange ant came to the larve. On January 18 I put out some more larve in the srnall porcelain cups. Between 8 and 9 both these ants found them, and kept on coming all day up to 7 P.M., when I left off observing. There were a good many ants wandering about in the box; but up to 4 o’clock only four came to the larve. Two of them I impri- soned as usual; but two (which came at 4.30 and 4.36) I marked. These went on working quietly with the first two till I left off observing at 7 p.M.; and during this latter time only three other ants found the larve. On January 31 I watched another specimen. At 9.14 I put her into a small cup containing a number of larve. She worked continuously till half-past seven in the evening, when I left off watching. During that time she had made more than ninety journeys, carrying each time a larva to the nest. During the whole time not a'single other ant came to the larvae. Again, on February 7, I watched two ants in the same manner. At 7 a.M. I put some larve in the small china cups. Up to 8 noants hadcometothem. Soon after 8 I put two marked ants, neither of them being the same as these whose movements are above recorded. 372 EXPERIMENTS ON CO-OPERATION. They were then watched until a quarter to eight in the evening, during which time one of them had made twenty-six journeys, carrying off a larva each time ; the other forty-two. During this period of about eleven hours, two other ants had come to the cup at which these were working, and the same number to one of the other cups. None of these ants, therefore, though they had found a large number of larve, more than they could carry in a whole day, summoned any other to their assistance. Again, February 7, 1875, I put some larve in three porcelain cups in the feeding-box of a frame containing a nest of Lasius flavus, about six inches from the entrance of the frame, and put, at 8 and 8.29 a.m. respectively two ants to the larve in the left-hand cup. They each carried off a larva and returned as follows :-— No. J. No. 2. At 8.38 — returned again and took another. 9. 0 = ” ” 9.7 ” ” 9.20 ” ” 9.30 ae 9 ” 9.43 ” 99 9.54 <7, ” ” 9.56 » %» 10.20 or » 30.25 —_ At 10.43 another ant came to the larvee in the oe cup. I imprisoned her. 11. 0 returned again and took another. ‘, 1 aes ” ” 11. 9 a Wis = . s 11.20 2 2 11.29 ” » EXPERIMENTS ON CO-OPERATION, 373 At. 11.37 — returned again and took another. 11.40 11.52 . . At 12.2 another ant came to the larve in the left- nand cup. I imprisoned her. 2” ” At 12. 3 — returned again and took another 12.15 55 3 12.30 “ 55 12.37 —_— +5 3 12.41 5 3 12.50 33 5 12.58 35 + 1. 0 ive ” ” 1.7 ” ” 1.12 eee ” ” 1.16 ” » 1.28 09 ” 1.32 a ” ” 1.35 ” 99 1.44 9 ” 1.50 a ” ” 1.55 ” ” 2. 6 ” ” 2. 9 — ” ” 2.17 ” ” 2.29 ” 2 2.39 a ” ” 2.42 ” » 2.49 2.49 35 *5 3. 0 = ” ” 3. 3 29 ” At 3.10 another ant came to the left-hand cup. | imprisoned her. At 3.14 returned again and took another, 3.15 oe) 2” 3.2 4 ” ” 374 EXPERIMENTS ON CO-OPERATION. At 3.31 3.34 3.36 — At 4.10 another ant came to the middle cup. imprisoned her. At 4.45 5.50 6. 2 6. 2 6.17 6.26 6.46 6.52 7.7 7.13 7.18 7.48 7.48 ” 9 ” ” ” ” ” ” ” ” ” ” 2 — returned again and took another. 29 ” — returned again and took another. ” ” ” ” ”° 2? ”» ” ” ” 99 After this they were not watched any more. be observed that the second ant made many more visits than the first—namely, forty-two in about eleven hours, as against twenty-six in eleven hours and a half. During this time two ants came to the larve in the cup they were visiting, and three to the other two cups. The following case is still more striking. On July 11, 1875, at 11 a.M., I put a Lasius flavus to some pupe of the same species, but from a different nest. She made eighty-six journeys, each time carrying off a pupa with the following intervals. Commencing— At .1. 0 11. 5 she returned. 11. 9 returned again. 11.16 again. 11.20 ,, 11.24 ,, 11.26 ,, At 11.29 again. 11.49 11.55 12. O 12. 5 12.16 12.30 ” ” ” ”° ” ” 1 It will EXPERIMENTS ON (O-OPERATION, At 12.40 again. 12.44 12.50 1. 1 1.10 1.19 1.27 1.33 1.43 1.49 1.52 1.56 2. 2 2.10 2.17 2.25 2.29 2.32 2.35 2.37 2.40 2.43 2.47 2.53 2.56 2.59 3. 2 3. 7 3.10 3.13 3.16 3.20 3.25 3.33 3.35 3.38 ” ” ” ” ” 2 29 29 ” 9 ” ” 9 99 oP 93 ” 9 2 29 ” 39 9 oP re Pe ” 29 bd of 3 9 rh ” ” At 3.40 again, 3.47 3.53 3.57 4. 0 4. 3 4.5 4. 8 4.12 4.15 4.18 4.20 4.23 4.26 4.30 4.33 4.40 4.43 4.45 4.49 4.53 4.55 4.58 5. 3 5. 7 5.12 5.19 5.22 5.28 5.28 5.32 5.35 5.39 5.50 7. 5 7.12 ” ” ”° 9 ” 3 9 3” 9 ” ” ” oe] 3 9 ” oP 9 9 9 ” ” ” ” ” ” 2 ” ” ” ” ” 33 ” ” 876 376 EXPERIMENTS ON After which she did not. come again till 8, when we left off watching. During the whole of this time she did not bring a single ant to help her. Surely it would have been in many respects desirable to do so. It will be seen that some of the pupe remained lying about and exposed to many dangers from 11 a.M. till 7 P.M.; and when she left off working at that time, there were still a number of the pupe unsecured; and yet, though she had taken so much pains herself, she did not bring or send others to assist her in her efforts or to complete her work. I have given the above cases at length, though I fear they may appear tedious and prolix, because they surprised me much. No doubt it more frequently happens that if an ant or a bee discovers a store of food, others soon find their way to it, and I have been anxious to ascertain in what manner this is effected. Some have regarded the fact as a proof of the power of communication; others, on the contrary, have denied that it indicated any such power. Ants, they said, being social animals, naturally accompany one another; moreover, seeing a companion coming home time after time with a larva, they would naturally conclude that they also would find larvae in the same spot. It seemed to me that it would be very interesting to determine whether the ants in question were brought to the larve, or whether they came casually. I thought therefore that the following experi- ment might throw some light on the question, viz.: to place several small quantities of honey in similar situations, then to bring an ant to one of them, and subsequently to register the number of ants visiting each of the parcels of honey, of course imprisoning for the time every ant which found her way to the honey except the first. If, then, many more came to the honey which had been shown to the first ant than to the other parcels, this would be in favour of their POWER OF COMMUNICATION. 377 possessing the power of communicating facts to one another, though it might be said they came by scent Accordingly, on July 13, 1874, at 3 p.m., I took a piece of cork about 8 inches long and 4 inches wide, and stuck into it seventeen pins, on three of which I put pieces of card with a little honey. Up to 5.15 no ant had been up any of these pins. I then put an.ant (Lasius niger) to the honey on one of the bits of card. She seemed to enjoy it, and fed for about five minutes, after which she went away. At 5.30 she returned, but went up six pins which had no honey on them. I then put her on to the card. In the mean time twelve other ants went up wrong pins and two up to the honey; these I imprisored for the afternoon. At 5.46 my first ant went away. From that time to 6 v’clock seven ants came, but the first did not return. One of the seven went up a wrong pin, but seemed surprised, came down, and immediately went up to the right one. The other six went straight up the right pin to the honey. Up to 7 o'clock twelve more ants went up pins—eight right, and four wrong. At 7 two more went wrong. Then my first ant returned, bringing three friends with her; and they all went straight to the honey. At 7,11 she went home: on her way to the nest she met and accosted two ants, both of which then came straight to the right pin and up it to the honey. Up to 7.20 seven more ants came and climbed up pins—six right, and one wrong. At 7.22 my first ant came back with five friends; at 7.30 she went away again, returning at 7.45 with no less than twenty companions. During __ this experiment I imprisoned every ant that found her way up to the honey. Thus, while there were seven- teen pins, and consequently sixteen chances to one, yet between 5.45 and 7.45 twenty-seven ants came, net counting those which were brought by the original ant ; and out of these twenty-seven, nineteen went straight up the right pin. Again, on the 15th July, at 2.30, I 26 378 EXPERIMENTS ON put out the same piece of cork with ten pins, each with a piece of card and one with honey. At 4.40 I put an ant to the honey; she fed comfortably, and went away at 4.44, At 4.45 she returned, and at 5. 5 went away again. » 5.40 ig Fe 5.55 9 » 6.13 35 and again at 6.25 and 6.59. There were a good many other ants about, which, up ta this time, went up the pins indiscriminately. At 7.15 an ant came and went up the right pin, and another at 7.18. At 7.26 the first ant came back with a friend, and both went up the right pin. At 7.28 another came straight to the honey. At 7.30 one went up a wrong pin. », 7.31 one came to the right pin. » 7.36 34 a with the first ant, ” 7.39 +P) 29 99 7.40 ” bes ” 7.41 ” 9 ‘9 7.43 5 3 9 1-45 a 5 39 7.46 2” ” y 3 <5 wrong pin. 8 +P) ” » (47 two ,, 34 » 7.48 one ,, right pin. 5 the first ant came back. », 7.49 another ant came to the right pin yy 7.50 ” ” Wrong 55 yy 7.51 ” ” right ” » three ants ,, Wrong 4, », 7.52 one ant 53 right ,, » 1.55 5, ” WON 99 ” ” right 4 ” i COO 55 6 WIONE 55 POWER OF COMMUNICATION. 379 At 7.58 one ant came to the right pin. 9 7.59, ” WYONng 55 Thus after 7 o’clock twenty-nine ants came; and though there were ten pins, seventeen of them went straight to the right pin. On the 16th July I did tae same again. At 6.25 I put an ant to the honey; at 6.47 she went. At 6.49 an ant came to the right pin. » 6.50 another 9 ” » 6.55 ,, ” ” » 656 4, » Wrong pin, and then to the right one. » 6.58 5 » vight pin. ” 7. 0 ” ” ” » 7. 5 the first ant came back, and remained at the honey till 7.11. >», ¢. 5 another came to the right pin; but she was with the first. », 7. 6 another ant came to the right pin. » 1. 6 ” sy Cake 5 @018 These two ants were met by the first one, which crossed antennz with them, when they came straight to the honey. ” ” oo ” 3 » a9 ” At 7.14 another ant came straight to the honey. ,, 7.21 the first ant returned ; at 7.26 she left. » 7.24 another ant came, but went first to a wrong pin, and then on to the right-one._ 55 an ant came to wrong pin. ” * ” ” vied ” bP) ” ” 7.34 ” ” ” 7.35 ”° 99 29 » 7.38 the first came back, at 7.45 went away again. 29 380 EXPERIMENTS ON At 7.42 an ant went to a wrong pin. » UAT ” ” ” » 7.48 ” ” ” sy 7.49 ” ” » 1.52 » the right pin. » 1.55 the first ant returned, and at 7.56 went away again. » 7.57 an ant went to wrong pin. » 7.58 ‘ right ,, » 8. 0 » wrong >, ” right ,, » 8 1 3 wrong ,, After this, foran hour no more ants came. On this secasion, therefore, while there were ten pins, out of thirty ants, sixteen came to the right one, while four- teen went to one or other of the nine wrong ones. July 18.—I put out the boards as before at 4 o’clock. Up to 4.25 no ant came. I then put one (No. 1) to the honey; she fed for a few minutes, and went away at 4.31. At 4.35 she came back with four friends, and went nearly straight to the honey. At 4.42 she went away, but came back almost directly, fed, and went away again. At 4.57 she returned, and at 5.8 went away again. 5, 4.45 an ant came to wrong pin. 29 4.47 ” Eb) 32 4.49 29 ” » 4.50 5 right pin 9 4.52 3% 5 9 4.55 35 wrong pin. » 4.56 “ right pin. This ant (No, 2)1 allowed toreturn tothe nest, which she did at 5.23, » 5. 6 as right pin. » 5.11 ” wrong pin. POWER OF COMMUNICATION. 381 At 5.12 an ant came to right pin. I changed the pin. » 5.16 an ant came to the pin which I had put in the same place. 5 a right pin. O19 ” 9» 5.20 two ants iy with No, 2. » ant No.1 e and went at 5.25. » 6.25 an ant a This ant had been spoken to by No, 2. » 5-26 another aut 53 99 5.35 ” ” 9 5D. 37 ” ” 5» 5.40 : » 0.41 ant No. 1 5 and went at 5.49 », 5.45 another ant - » 0.50 35 Ee 51 ant No. 1 came back, and 5.54 went. », 5.58 twoants came to the ‘right pin. ») 5.59 another ant re a came to a wrong pin. I changed the pin again. », 6.49 an ant came to the pin which I had put in the same place. » 7 1 another ant came to the right pin. 99 7.20 ” ” oes » 7.46 ant No. 1 returned, 7. 55 went. A ” Thus during this time, from 4.50 until 7.50, twenty- niue ants came, twenty-six went to the right pin, while only three went up any of the nine wrong ones. More- over, out of these twenty-six, only four were distinctly brought by the two ants which I had shown the honey. On the 19th I tried a similar experiment. The uurked ants frequently brought friends with them ; but, 382 EXPERIMENTS ON without counting these, from 3.20 to 8 o'clock, out of forty-five ants, twenty-nine went up the right pin, while sixteen went up the nine wrong ones. Thus on July 13, out of 27 ants, 19 went right and 8 wrong. 9 15 ob 29 ”? 17 ” 12 ” > 1 6 ” 30 > 16 ” 14 ” » 18 5 26 4 23 09 3» ” 19 ” 45 a 29 ” 16 ” Or adding them all together, while there were never less than ten pins, out of 156 ants, 103 came up the right pin, and only 53 up the others. I was at first disposed to infer from these facts that the first ant must have described the route to its friends, but subsequent observations satisfied me that they might have found their way by scent. POWER OF COMMUNICATION. 383 APPENDIX E. Tne following are the details of the experiment referred to in p. 168 :— January 24, 1875.—I put an ant, which already knew her way, on the larvee at 3.22. At 3.30 she returned. 4.15 93 At 3.38 another ant came; and 4.25 as the bridge /f being 4.34 Se turned towards m, shewent over it tom. 4.42 ,, 3.50 z - 4.50, 4.35 . “ 4.56 5 5.15 45 i At 5. 5 she returned. 5.14 . 5.25 . January 25.—6.30 a.M. put two ants, which knew their way, to the larve. No. 1. No, 2. Returned 6.55 a 7.7 Returned 7.11 RB 5 7.27 s 7.35 <5 7.46 ai 1.47 384 EXPERIMENTS ON No. 1. No, 2. Returned 7.49 Returned 7.51 5 7.53 3 7.57 *5 8. 0 is 8. 3 5 8. 8 8.16 an ant to ™ ° 8.17 ss 8.18 e 8.21 8.22 5 Ks 8.25 c 8.25 s 8.29 8.30 ae 8.31 — 8.34 i 8.35 » «8.36 = 8.40 4 8.40 - 8.44 8.45 s a5 8.46 * 8.47 me 8.51 3 8.51 - 8.55 5 8 5? a (8038 5 9. 8 918 n 924 39 9.2 «930 «982 » 984 POWER OF COMMUNICATION, 385 No. 1, Returned 9.37 ” ” 39 9 ” 2 29 29 oP 2 29 ” 99 2 29 ” ” ” ” 9.43 9.45 9.47 9.50 9.55 9 58 10. 1 10. 7 10.10 10.16 10.18 10.20 10.22 10.24 10.28 10.32 10.35 10.38 10.42 10.45 10.48 10.51 10.53 10.55 No. 2. Returned 9.35 ” oe 9.43 9.45 9.51 9.55 9.58 1.10 10. 7 10.10 10.15 10.17 10.20 10.22 10.30 10.33 10.35 10.39 10.42 10.46 10.49 10.51 10.53 9.44 an ant to m 10.11 386 Returned ” 3”? ” ” 2? 9” ” ” ” ” ” ” 9% ” ” ” 9 » ” ” ” EXPERIMENTS ON No, 1. No, 2. 10.58 Returned 10.58 11. 0 yd 11. 2 1l. 5 11.10 11.12 11.16 11.21 11.23 » 11.24 11.26 » 11.26 11.30 » 11.30 11.35 » 11.35 11.36 11.40 » 11.40 » 11.43 11.45 » 11.45 11.46 » 11.50 » 11.51 » 11.56 11.58 » 11.59 12. 0 12. 2 si bDE-2 12. 6 » 12.6 12.10 4, 12.10 12.14 12.16 12.20 » 12.20 12.24 » 12.30 1 2 11.15 another ant tom 11.40 4 1142 96 12.20 ,, dropped. imprisoned her. POWER OF COMMUNICATION. 3387 No, 1 No, 2. Returned 12.31 12.35 an ant tom » 12.36 » «1244 » 12.46 » 12.50 5» «O24 » «1259 : id I then put her into a small bottle. I let them out again at 7.10 on the 27th. Though the interval was so long, they began at once to work ; but one unfortunately met with an accident. The other returned as follows, viz. at 7.20 7.30 7.40 7.48 stranger to m. 7.46 7.51 7.55 7.59 In these experiments, therefore, 17 unmarked ants came ; but at the point n they all took the wrong turn, and not one reached the larvae. 388 EXPERIMENTS ON APPENDIX F, TuE following are the details referred to on p. 168 :— January 27, 1875.—At 5.30 I let out the same two ants as were wnder observation in the preceding experi- ments. No 1. No. 2. Returned at 5.40, the other not till 6.49 3 eed 9 ”» ” 99 ” ” ” ” ” ” ” ” ” ” 6. 0 6. 8 6.26 6.32 6.37 6.41 ” > ” cd 9 ” 9 6.22 an ant tom. 6.49 6.50 6.52 3 7. O 6.53 an ant to larvee. 7.27 an anttom wOnNNrHe PONWnNNW SD I then put them into the bottle, POWER OF COMMUNICATION, 389 January 28.—Let them out at 6.45. No. 1. Back at 7. 0 ” 2” ” ” ” 3° 2 3° > 22 oP ” 29 9 7. 5 7.11 7.16 7.2) 7.27 7.45 7.52 8. 2 8.11 8.20 8.26 8.30 8.36 8.40 8.44 8.48 No, 2. 7.3 7.12 7.31 an ant to m, 7.32 7.42 She dropped into some water. I then put them into the bottle. January 29.—I let them out at 7.35 A.M. No. 1 returned at 7.47, after which I saw her na I fear she must have met with an accident. No. 2 returned at more. 7.56 8. 8 8.18 8.28 8.35 8.42 8.48 390 EXPERIMENTS ON 8.50 another ant came to the larva; marked her No. 3. No. 3. 9.20 2 ants to larvee. 9.47 5 ants to m. At 9.40 I found one of the ants which had been ander observation on the 24th, and put her to the larvee She returned as follows (No. 4):— No. 2, 9.58 10.10 10.20 10.37 10.41 10.44 10.48 10.53 No. 3. No. 4. 9.50 9.52 9.55 10. 3 10.12 10.15 10.20 10.23 10.26 10.26 10.29 10.33 10.36 10.40 10.41 10.44 10.51 10.56 No. 1. 10.59 11.4 11. 9 11.17 11.28 11.33 11.40 11.47 12. 0 POWER OF COMMUNICATION. 391 No. 2. 10.59 11. 2 11.17 11. 9 11.13 11.16 11.20 11.23 11.26 11.30 11.33 11.42 11.46 11.50 11.54 11.58 12. 1 No. 3. 10.57 ll. 2 11.10 11.14 11.18 11.23 11.44 11.50 11.54 1l. 5 an ant to arvw. we «x. & 90 4 11.21 ” ” 11.22 an ant to m 11.25 an ant to larvae. 1155 & 3S 11.55 an ant to m. in 6 & 392 No, 1. 12.10 12.15 12.27 12.36 1.13 1.22 1.44 EXPERIMENTS ON No, 2. 12. 8 12.13 12.18 12.25 12.30 12.36 12.40 12.43 12.47 12.50 12.53 12.56 12.59 1.7 1.12 1.55 No. 3 12.14 12.24 12.57 1.0 1.7 1.18 1.25 1.33 1.41 1.51 1.56 2. 9 2.35 POWER OF COMMUNICATION. 393 I then put her into a small bottle. We kept a look- out for Nos. 2 and 3 till 7.30 p.m.; but they did not return. January 30.—Let No. 4 out at 7 am. She returned at 7.45. No. 3 came) of herself at}: 0 No. 4. Returning at 8. 9 8. 6 8.15 another ant to larve, ” 8.20 8.25 ” 8.30 ” 8.36 No. 3. No. 4. Returning at 8.40 8.43 8.51 an ant tom. ” 8.52 3. 3 ” 9. 5 Imprisoned them. Let them out at 10.55. Returning at 11. 1 11. 3 11. 8 es 11. 9 1’.14 another ant to m. And they went on coming regularly till 1, when I put them again into a bottle. Janwary 31.—-Let them out at 6.35 a.M. No 3. No. 4. 6.55 7.12 7.15 7.21 394 EXPERIMENTS ON No. 3, No, 4. 7.29 7.37 7.42 7.42 7.48 7.53 7.55 another ant to 8. 0 7 8. 1 8.12 8.18 8.20 8.24 = 8.27 8.28 8.32 8.36 an ant to larva, 8.39 8.44 I imprisoned them. January 31.—Let them out at 5.35 P.M. No. 3. No. 4. 5.47 7.23 another ant to larva. 7.26 7.27 ‘5 Me POWER OF COMMUNICATION. 395 No. 3. : 7.29 another ant to m. 7.30 7.30 59 larvee. Im prisoned her 7.31 Fe Mm. February ‘1.—Let her out at 7.5. No. 3. She returned at 7.20 . 7.30 as .7.88 another ant to m. 33 7.40 55 7.48 5 7.58 7.59 a ‘ 8. 6 : 8.12 8.14 " 8.17 3 - 8.22 Imprisoned her and let her out again at 6.20 P.M. ‘She returned at 6.35 . 6.52 : 7.0 7.5 7 7.15 i 7.20 7.95 Imprisoned her. February 2.—Let her out at 6.30 a.m. She returned at 6.50 - 7. 0 7. 2 another ant to m. ‘a Tet 7.10 two otherants tom ” 7.13 396 EXPERIMENTS ON She returned at 7.17 7.27 another ant to larve, = 7.28 a9 7.36 7.38 + m. 4 7.45 3 7.50 7.51 si ~ rs 7.55 a 8. 4 ss 8.11 . 8.18 7 8.25 “ 8.30 _ 8.35 . 8.45 8.46 Imprisoned her. In this experiment, then, the bridge over which the marked ant: passed to the larvee was left in its place, the scent, however, being removed or obscured by the friction of my finger; on the other hand, the bridge had retained the scent, but was so placed as to lead away from the larve; and it will be seen that, under these circumstances, out of 41 ants which found their way towards the larve as far as ¢, 14 only passed over the bridge f to the larve, while 27 went over the bridge d to the empty glass m. Taking these observations as a whole, 150 ants came to the point e, of which 21 only went on to the larvee, while 95 went away to the empty glass. These experiments, therefore, seem to show that when an ant has discovered a store of food and others flock to it, they are guided in some cases by sight, while in others they track one another by scent POWER OF COMMUNICATION. 395 APPENDIX G. THE following are the details of the experiment referred to on p. 172 :— Experiment 1.—Time occupied, 1 hour. The ant with few larvw: made 6 visits and brought no friends. The one with many larve' made 7, and brought 11 friends. Experiment 2.—Time occupied, 2 hours. The ant with few larva made 13 journeys, and brought 8 friends. The one with many larve did not come back. Experiment 3.—Time occupied, 3 hours. The ant - with few larve made 24 journeys, and brought 5 friends. The one with many larve made 38 journeys, and brought 22 friends. Experiment 4.—-Time occupied, 2} hours. The ant with few larvee did not come back. The one with many made 32 journeys, and brought 19 friends. Experiment 5.—Time ocupied, 1 hour. The ant with few larve made 10 journeys, and brought 3 friends. The other made 5 journeys and brought 16 friends. . Experiment 6.—Time occupied, 1} hour. The ant with few larve made 15 journeys, but brought no fiiends. The other made 11 journeys and brought 21 friends. Experiment 7.—I now reversed the glasses. Time wccupied 3 hours. The ant with few larve made 23 icurneys and brought 4 friends. 398 EXPERIMENTS ON Experiment 8.—Time occupied, 14 hour. The ant with few larvee made 7 journeys and brought 3 friends. The one with many larve made 19 journeys and brought G friends. ; Experiment 9.—Time occupied, 1 hour. The ant with few larvee made 11 journeys and brought 1 friend. The one with many larve made 15 journeys and brought 13 friends. Experiment 10.—I now reversed the glasses, the same two ants being under observation ; so that the ant which in the previous observation had few larve, now consequently had many, and vice versa. Time occupied 2 hours. The ant with few larve made 21 journeys and brought 1 friend. The one with many larve made 32 journeys and brought 20frienls. These two experi- ments are, I think, very striking. Experiment 11.—Time occupied, 5 hours. The ant with few larve made 19 journeys and brought 1 friend. The one with many larve made 26 journeys and brought 10 friends. Experiment 12.—Time occupied, 3 hours. The ant with few larvee made 20 journeys and brought 4 friends. The one with many larve brought no friends and made 17 journeys. Experiment 13.—Time occupied, 1 hour. The ant with few larva made 5 journeys and brought no friends, The one with many made 10 journeys and brought 16 friends. Experiment 14.—I now reversed the glasses. Time occupied, 24 hours. The ant with few larve made 10 journeys and brought 2 friends. The other made 41 joarneys and brought 3 friends. Experiment 15.—Time occupied, 44 hours. The ant with few larvee made 40 journeys and brought 10 friends. Of these, 8 came at the beginning of the ex- periment, and I much doubt whether they were brought ; during the last hour and a half she only brought 1 POWER OF COMMUNICATION. 399 friend. However, I think it fair to record the observa- tion. The ant with many larve made 47 journeys and brought 1 friend. Experiment 16.—Time, 44 hours. The ant with few larvae made 20 journeys and brought 1 friend. She did not return after the first 2 hours. The other ant made 53 journeys and only brought 2 friends. This latter was the same one as in the previous experiment, when, however, she had the glass with only two or three larvee. Experiment 17.—Time, 1 hour. The ant with few larve made 6 journeys and brought no friend. The one with many larvee made 11 journeys and brought 12 friends. Experiment 18.—Time, 14 hour. The ant with few larve made 25 journeys and brought four friends. The one with many larve made 20 journeys and brought 15 friends. Experiment 19.—Time, 44 hours. The ant with few larvae made 74 journeys and brought no less than 27 friends. This is quite in opposition to the other observations ; and I cannot account for it. She was the ant who brought 15 friends in the previous experi- ment, and it certainly looks as if some ants were more influential than others. The ant with many larvae made 71 journeys and only brought 7 friends. Experiment 20.—Time, 2 hours. Theant with few larvae made 35 journeys and brought 4 friends. The one with many larve made 34 journeys and brought 3 friends. Experiment 21.—I now transposed the two glasses. Time, 14 hour. The ant with few larve made 15 journeys and brought no friends. The other made 35 journeys and brought 21 friends. Experiment 22.—I now transposed the glasses again. Time, 2 hoars. The ant with mary larve made 400 EXPERIMENTS ON POWER OF COMMUNICATION, 27 journeys and brought 9 friends. The ant with few larvee made 18 journeys and brought no friend. This, I think, is a very striking case. She was under observa- tion 54 hours; and the scene of her labour was the same throughout. The first 2 hours she had few larve and brought 4 friends ; then for 14 she had many larve and brought 21 friends; then again for 2 hours she had few larve and brought no friend. Faperiment 23.—Time, 14 hour. The ant with few larvee made 25 journeys and brought 3 friends. The other made only 9 journeys, but brought 10 friends. Experiment 24.—I now transposed the glasses. Time occupied, 2 hours. The ant which now had few larvee made 14 journeys, but brought no friends. The other made 37 journeys and brought 5 friends. Expervment 25.—Time 3 hours. I put an ant for an hour to a full glass; she made 10 journeys and brovght 4 friends. I then left only two or three larve: in the second hour she made 7 journeys and brought no friend. I then again filled the glass; and during the third hour she made 14 journeys and brought 8 friends EXPERIMENTS ON CO-OPERATION. 401 APPENDIX H. Tue following are the detailed observations on bees alluded to in Chapter X. August 24.—I opened the postern door at 6.45, and watched some marked bees till the middle of the day. Bee No. 1. 6.50 One came to the honey. She then flew to the window, but after buzzing about for some time returned to the hive. 7.21 back to honey. 7.23 back to hive. 7.26 back to honey. 7.30 flew to window and then fell on the floor. I was afraid she would be trodden on, so at 7.45 I showed her the way to the hive. 8.40 back to honey. 8.45 back to hive. I now closed the postern door till 10.15. 10.35 back to honey. 10.39 to hive. 10.45 5 and then to hive. 12.35 7 12.37 to hive again. Bee No, 2. 7. 0 she cametothe honey. 7. 5 she went back to hive, 7.12 back to the honey. 7.22 5 7.24 . 7.30 if 7.42 . 7.46 a 7.52 A 7.57 js 42 COMMUNICATION AMONG BEES. 8. 5 back to the honey. 8. 9 she went back to hive, 8.15 a3 8.20 : 8.26 8.30 7 8.40 3 8.44 ‘ 8.55 - 9. 0 @ I then closed the door till 10.15; at 9.5, however, she came round to the honey through an open window, but could not find her way back, so I had to put her into the hive. 10.15 back to the honey. 10.17 shewentback to hive, 10.20 55 10.23 a 10.30 55 10.33 10.50 ” 10.55 Ss 11. 1 3 11. 6 » 11.17 3 11.23 »” 11.33 ” ? ” 11.45 es 11.50 ” 12. 0 a5 12. 3 5 12.10 9 12.15 9 12.24 <5 12.30 99 12.37 ” 12.43 % 12.52 ” 12.56 ” Bee No. 3. Also on August 24. 10.16 came to honey. 10.19 returned to hive, 10.30 i 10.34 . 10.55 _ 10.57 : ll. 2 . 11. 5 is 11.11 ‘ 11.15 = 11.24 11.27 ‘ 11.35 pi 11.37 = 11.45 3 11.47 A 11.57 ? x 12.13 5 12.16 eS COMMUNICATION AMONG BEES. 403 12.26 came to honey. 12.30 returned to hive. 12.36 2 12.42 i 12.56 7 12.59 9 The next day I timed this bee as follows :— 7.23 came to honey. 7.25 returned to hive. 7.35 i 7.37 ‘5 7.44 ‘5 7.45 ss 8.10 - 8.12 - 8.53 G 8.55 (The door was then closed till 9.30.) 9.35 Pa 9.40 to window, and at 9.49 to hive. 10. 0 és 10. 5 returned to hive. 10.13 10.15 - 10.22 = 10.26 cs 10.35 : 10.40 - 10.45 . 10.48 : 10.56 . ? i 11.7 a 11.12 . 11.18 11.20 . 11.35 ‘ 11.37 di 11.47 % 11.51 a 12. 2 7 12. 6 fe 12.25 A 12.29 a 12.51 - 12.54 ’ During these observations scarcely any unmarked bees came to the honey. In these cases the postern, being small and on one side, was not very easily found. If the honey had been in an open place, no doubt the sight of their com- panions feasting would have attracted other bees; but the honey was rather out of sight, being behind the hive entrance, and was, moreover, only accessible by the narrow and winding exit through the little postern door. But, however exposed the honey might he, [ found 104 COMMUNICATION AMONG BEES, similar results, unless the bees were visible to their fellows. Of this it may be well to give some detailed evidence. Thus, one morning at 9.19 { I brought a bee } 9.94 fs returned to to some honey. the hive. she came back ee { to the honey. \ ais v 10. 8 s 10.10 i, 10.16 ne 10.19 - 10.28 < 10.30 3 10.37 “3 10.40 . 10.50 - 10.53 ce 11, 0 . ll. 4 11.11 - 11.15 a 11.22 5 11.27 ” 11.34 “ 11.37 ” 11.46 2 11.50 a 11.55 a 12. 0 29 12. 6 s 12. 7 ” 12.40 ‘5 12.46 9 12.54 . 12.57 - 1. 2 . 1. 4 a Flew about. 1.15 Fe 1.18 ‘5 1.23 7 1.27 - 1.34 7 1.41 : 1.54 - 2. 0 . After which she did not return. During this time no other bee came to the honey. Again on another occasion I watched several bees, whick on my list of marked bees stood as Nos. 3, 4, 7, 8, 10, and 11. 9.45 bee No. 10 came. 9.50 went back to hive. Oo ae 10. 3 s 10.18 , 10 y 10.21 wae , 4 | 10.30 7 10.30 bee No, 4 came. 10.36 10.46 10.49 11.0 11. 5 11.11 11.21 11.22 11.26 11.30 ” 11.40 11.45 11.47 bP] 12. 1 12. 2 12. 3 12. 4 12.14 12.17 12.24 12.30 12.36 12.37 12.37 12.45 12.50 12.50 12.53 12.57 12.57 1. 0 1. 2 1.9 1.10 ” ” ” ” ” ” ” a strange bee No. 4 came. ”° 9 ” ” 2” COMMUNICATION AMONG BEES. Iwapw PA 7 10 4 7 10 ” ” ” EP] ”? 9 9 bee came. ”° 405 10.35 went back to hive. 10.45 10.52 10.52 11. 9 11. 9 11.16 11.29 11.31 11.39 11.36 11.45 11.50 11.59 another strange bee came. bee No. 4 came. 29 PD ” 29 29 29 — _ — pes ORNOPRNORTOORNON BRAC ON 9 29 oP 99 29 29 ” 29 ” 9 29 ” 29 ” ” 9 ” 39 29 ” 12. 6 12. 8 12. 7 12. 7 12.18 12.21 12.31 12.33 12.46 12.44 12.40 12.49. 12.54 12.54 12.56 1. 0 1. 2 ” ” ” ” > ” ” ” ” ” ” 99 9 ” ” ” 9 9 29 Eb ” ” ” ” ” ” ” ” ” ” 33 ” x” ” 406 COMMUNICATION AMONG BEES. 1.10 bee No. 7 came 1.16 went back to hive. Hi6 gs 4 1.19 e 1.17 yy 5 yy 1.21 ” 126° 4. FS 1.24 : 120 4 8 45 1.25 . Ul «ek As 1.24 1.23 ” 5» 1.27 ” 122 4, 4 gg 1.29 7 ” 9 After this I ceased recording in detail; but the above shows that while the marked bees came regu- larly, only in two cases did any unmarked bees come to the honey. In the above cases the honey was poured into saucers, but not weighed. In the following I used a wide-mouthed jar containing rather more than one pornd of honey. 1.44 bee No. 5 came. 1.45 went away. 164 sy D Gs 1.58 ke i a: 2. 5 : i one |: ae 29 », 1 2.15 is BIR) xg oR. 2.20 me OAG* ay She 2.21 es BOS? 4. Py 2.31 . 237 4, 1 4, 2.41 A B30) jae, Cb 2.40 ‘ 249 4 5 4 2.51 - 2.52 1 2.55 9 2 3.10 another came which I numbered as No. 14 3.11 bee No. 1 came. 3.13 went away. BO ak Bh gp 3.22 =, 320 | - 323 4, $19: id. 3.23 4, $20: a . 6 Sam | g3r 4, Ie « 3.33 i COMMUNICATION AMONG BEES, 401 3.37 bee No.1 came. 3.40 went away. Bae bs 3.42 * $38) ., 12 | 3.41 is 540 ax 2. & 3.49 i 3.46 4, 14 ,, 3.51 - She was 34 4. 14s 3.56 - | Sictorhed 20° a5. 1 4. 3 x BO yes Cie cay 4, 38 : AG ae TA 4.11 . AIO 4 BO 4.12 i. 415 | 14. 5 4,20 se 422 , 1 4 4.25 . 494 ,. 14 ,, 4.29 is a 4.29 . During the whole of this time only one strange bee came, as recorded above. In the following case I put out, besides one pound of honey, also four ounces of honey spread over two plates. 12.15 one of my marked _—12.21 she went. bees came. 12.26 she returned 12.31 +5 12.36 : 12.44, 12.51 : 12.57, 1. 4 “ iia) Je 1.15 - iio, 1.25 _ 132 4 1.38 i 144, 49 3 1.55 s 2. 0 , DF 4s 2.14 ” 2.19 ” 2.25 ” 2.33 39 2.38 3 2.44 *” 2.50 5 2.58 + 3. 5 = S15 3 COMMUNICATION AMONG BEES. 3.20 she returned. 3.32 she went. She wae 3.39 a 3.45 4, (disturbed. 3.52 . HD 55 4.7 5 4. 9 a 4.15 : 4.20 45 4.27 4 4.32 i 4.43 7 4.45 59 4.50 5 4,59 yg 5.7 - 513g 5.25 7 5.31 yy 5.42 . 548 4, 5.56 3 6. 1 sy 6.14 During this time no other bee came to the honey. I had, on August 20, introduced some bees to honey in my room, since which it had been much visited by them. On the 24th I put a bee to some honey inside a flower-pot five inches high and five wide at the base. The flower-pot was laid on its side, and the mouth closed,-so that: the bee had to come out through the hole in the bottom, which was about } an inch in dia- meter. To make things easier for her, I made her a small alighting-board of wood, the top of which was evel with the hole. I then placed the flower-pot on the spot where she was accustomed to find the boney. She had made her first visit that morning at 6.45, re- turning At 6.55 7.5 4 3. -1e7 ol 23. I then arranged the flower-pot as de- scribed, and put her, while feeding, into it: she found her way out without diffi- culty. At ~ 40 she returned, but did not seem able to find \ COMMUNICATION AMONG BEES, 409 her way; so I put her in. The same thing happened again at 7.50 8. 6 and 8.20 but at 8.88 she found her way in easily, and had no further difficulty. She returned at 8.53 9. 5 9.14 9.25 9.41 9.55. 10. 6. This time a friend came with her and followed her in. I captured her. No. 2 took no notice, but returned At 10.19 At 2.43 10.30 2.59 10.44 3.23 10.54 3.33 11. 6 3.44 11.20 3.56 11.31 4.7 11.44 4.21 11.55 4.34 12. 9 4.44 12.25 4.55 12.37 5.10 12.50 5.24 1, 2 5.35 1.14 5.46 1.25 5.58 1.36 6. 9 1.47 6.20 1.57 6.42 2. § 7. 0 2.19 7.15 2.31 making 59 visits. 28 410 COMMUNICATION AMONG BEES. After which she came no more that day. With the one exception above mentioned, during the whole time no other bee came to the honey. I might also mention that I had put out six similar flower-pots in a row, and that this seemed to puzzle the bee a good deal; she frequently buzzed about before them, and flew from one to the other before entering. When she went in, she generally stood still just inside the entrance for about. thirty seconds, buzzing loudly with her wings. I thought at first whether this could be intended as a sort of gong to summon other bees to the feast ; but though several were flying about, at any rate none came. The following day (August 25) she came at 6. 51, and had made nine journeys up to 8.41, when I left off watehing. During this time no other bee came. August 26.—She came at 6.32, and up to 8.43 had made thirteen journeys. August 27.—She came at 6.7, and up to 8.43 had made fourteen journeys. August 28.—She came at 6.17, and up to 7.11 had made five journeys. During these days no other bee came. On July 19 I puta bee (No. 10) to a honeycomh containing 12 lbs. of honey At 12.30 she returned. At 12.36 went back to hive 12.50 12.55 E 1. 6 - 1.12 d 1.53 is 1.57 “ 2.5 - 29 : 2.16 2.20 “4 2,28 : 2.32? 2 2.49 ‘ 2.55 3.13 < 3.20 : 3.31 i 3.39 is 3.45 3.5E . 4. 2 . 4. 8 7 COMMUNICATION AMONG BEES. 411 4.18 she returned. 4.24 went back to hive. 4.31 > 4.37 ‘ 4.47 . 4.58 . 5.10 2 5.19 ba 5.27 65 5.30 5 6. 9 Fe 6.15 55 6.23 . 6.29 . 7.19 a 7.24 ‘i 7.35 - 7.40 oy 7.50 ‘5 7.55 3 and during all this time no other bee came to the comb, On the following morning, July 20, this bee came to the honeycomb At 6. 5 aM. At 6.10 went back to hive. 6.37 she returned. 6.42 $5 7.17 e 7.21 is 7Al is 7.47 5 8. 8 8.12 7 8.21 a 8.25 8.32 Ss 8.54 - 9.4 - 9.9 - 9.45 3 9.51 ee 10. 4 : 10.10 10.19 10.26 . 10.40 : 10.47 : 10.59 ll. 4 - 11.14 . 11.19 11.44 s 11.52 = 11.59 5 12. 6 6 12.15 a 12.23 é 12.29 : 12.35 < 12.41 », (was dis- turbed) 12.52 i‘ 1. 2 i 1. 9 7 1.16 1.30 a 1.46 « 1.55 2 412 I then left off observing ; but during the whole of this time no other bee had come to the comb. October 9.—I took a bee (No. 11) out of the hive and put her to some honey: she returned and kept on visiting it regularly. October 10.—This bee came to the honey at +.30 a.M., and went on visiting it; but I was not able to watch her continuously. During these two days nc COMMUNICATION AMONG BEES. other bee came to this honey. October 11.—No. 11 came to the honey At 7.12 a.m., but did nct alight. 7.18 she returned. At 7.21 went back to hive 7.27 - 7.31 7.38 ‘ TAA 7.51 : 7.56 8. 2 i. 8. 8 8.15 35 8.22 8.30 - 8.35 8.41 2 8.46 8.55 ie 8.59 9. 6 5 9.11 9.20 9.25 9.45 5 9.50 9.55 u 10. 1 10. 7 « 10.11 10.19 10.23 ” ” 99 ” 99 ” ” ”° 2 ” ” ” ” 10.30 a strange bee came ; I killed her. 10.35 10.55 11, 4 11.26 11.35 she returned. At 10.40 went back to hive, 99 +e) ” oP) 10.59 11.8 11.30 11.38 Another strange bee came. At 11.52 she returned. At 11.55 went. 12. 7 ted 12.12 ”° 9 bb) ” 12.17 she returned. 12.31 12.58 1. 8 1.19 1.30 1.45 2. 2 2.15 2.29 2.45 2.50 2.57 COMMUNICATION AMONG BEES. ” ” ” 99 12.22 went. 12.36 1. 2 1.12 1.23 1.34 1.48 2. 6 2.18 2.35 2.47 2.52 3. 0 ” ” 29 bP ” 9 9 ” bd ” 9 oP 413 after which she did not come any more that day. It was, however, a bad day, and after 1 o’clock she was almost the only bee which came out of the hive. The following morning she came to the honey at 7.58 a.M., but did not alight, behaving just as she had done the day before. At 8. 6 a.m. No. 11 returned to honey. At 8. 9 went. 8.14 8.30 8.42 8.54 9. 9 9.19 9.29 9.37 9.54 Astrange beecame. At 9.59 No. 11 went. ” ” bP) ” ” ” ” ” 29 ” ” ” 2 bP ” 29 9 2” 8.20 8.34 8.46 8.59 9.14 9.24 9.33 9.44 99 ” °° ” ” ” ” 39 but was disturbed. \{ 10. 5 she returned to the honey. At 10. 8 went. 10.12 10.16 10.26 10.33 10.40 9 ” ” ” ” 29 ” ” 9 10.13 10.20 10.28 10.36 10.46 ” ” > ” 114 COMMUNICATION AMONG BEES. 10.55 a strange bee came. No. 11 returned to the honey regularly, and went on coming. October 13.—At 6.28 a.m. she came, but, as before, flew away again without alighting. At 6.32 she came to the honey. At 6.36 went away. 6.42 55 + 6.46 3 6.51 $5 $5 6.56 55 7.10 35 35 7.14 3 7.26 ‘5 6 7.34 39 7.46 59 35 7.50 $5 7.55 a <5 8. 0 9 8.12 x 35 8.15 55 8.20 73 3 8.26 7 8.30 6 5 8.33 35 8.37 3 us 8.44 *s 8.50 55 3 8.56 5 and so on. October14.—She came for the first time at 8.15 A.M., aud went on visiting the honey at the usual intervals. After this day 1 saw her no more; she had probably met with some accident. But these facts show that some bees, at any rate, do not communicate with their sisters, even if they find an untenanted comb full of honey, which to them would be a perfect Eldorado. This is the more remarkable because these bees began to work in the morning before the rest, and continued to do so even in weather which drove all the others into the shelter of the hive. That the few strange bees which I have recorded should have found the honey is natural enough, because there were a good many bees about in the room. My room, I may add, is on the first floor ; if it had been on the level of the ground I believe that many more bees would have found their way to the honey. I will now proceed to the similar observations made with wasps. EXPERIMENTS WITH WASPS. 415 The first one, I believe a worker of Vespa Germanica, | marked and put to some honey on September 18. The next morning she came for the first time at 7.25, and fed till 7.28, when she began flying about the room, and even into the next; so I thought it well to put her out of the window, and she then flew straight away to her nest. My room, as already mentioned, had windows on two sides; and the nest was in the direction of a closed window, so that the wasp had to go out of her way in passing out through the open one. At 7.45 she came back. I had moved the glass containing the honey about two yards; and though it stood conspicuously, the wasp seemed to have much difficulty in finding it. Again she flew to the window in the direction of her nest, and I had as before to show her the way out, which ¥ did at 8.2. At 8.15 she returned to the honey almost straight. At 8.21 she flew again to the closed window, and apparently could not find her way, so at 8.35 I put her out again. It seems obvious from this that wasps have a sense of direction, and do not find their way merely by sight. At 8.50 back to honey, and 8.54 again to wrong window; but finding it closed, she took two or three turns round the room, and then flew out through the open window. At 9.24 back to the honey, and 9.27 away, first, however, paying a visit to the wrong window, but with. out alighting. \t 9.36 back to honey; 9.39 away, but, as before, going first to wrong window. She was away, there- fore, 9 minutes. 9.50 back to honey ; 9.53 away.! Interval 11 minutes «.0 =, » 107 » Ll ! This time straight. 2? 416 COMMUNICATION. 10.19 back to honey; 10.22away. Inteival 12 minutes 10.35 ,, » 1029 , mes Slee ke WAT, » 10.50 ,, se as 11.4 ,, ” 1l7 ” 14 ” 11.21 ,, ao. bed: | ae en 11.34 ,, me: LOT es ey AD x 11.49 ,, 5 M152) cals sas 12.3 5, ” 12.5 ,, ” 11 Eo) 1.13 4 » TU 4 8) ce 12.25 ,, » (ce ae ae es 12.39 ,, » 12.438 ,, mt fay oe 12.54 ,, « 1257 5 a, Jtde cy 1.15 ,, ” 119 ,, ” 18 ” 1.27 ” ” 1.30 ,, ” 8 ” Here for the first time another specimen came to the honey. At 1.37 back to hovey; 1.39 away.! 146 ,, a 1.49 4, Interval 7minutes. 1.54 > 29 1.58 oT ” 5 a> 2. 5 ” ” 2. 7 9 +P) 7 ”? 2.15 > ” 2.19 ” bP) 8 ” 9.27? ; 2.32 4, ss 8 33 2.39 ” ” 2.42 be) PP) 7 ” 2.50 4, i 2.54 45 ys 8 - 3. 2 ” ” 3. 6 ” ” 8 9” 3.14 ” 39 3.17 9” ” 8 39 3.26 ” ” 3.29 ” ” 9 ” 3.38 ” PP} 3.42 ” 29 9 ” 3.50 oP) - 99) 3.58 ” ” 8 ” 4, 7 ” ” 4.12 9 ” 9 ” 4.20 ” +b) 4.23 ” ” 8 ”? 4.32 9 ” 4.36 bP 99 9 ” \ Was rather disturbed, as I tried to mark her. 2 She very often, however, throughout the day, in going away, Glew to the other window first, and then, without alighting, returned to and went through the open one COMMUNICATION. 47 4.46 back to honey; 4.49 oe Interval 10 minutes, 5. 5. 0 29 99 ” 99 11 9 5.13 ,, » Oe 17 » » 10 5 5.26 » 29 5. 30 > 2 9 ” 5.40 ,, ” 5.44 ,, » 10 4s 5.54 5, is 5.59 ,, » Wo y 6. 7 ” ”? 6.11 9 bb) 8 ” 6.20 9 99 6.25 ” ” 9 ” She did not come any more that day; but, as will be seen, she had made forty-five visits to the honey in eleven hours. During the whole of this time no strange wasp, except the one above mentioned, came to this honey. The following day, September 20, this wasp made her appearance in my room at 6.55, when she flew straight to the honey. At 6.55 came to honey; 6.59 went away. 7. 8 7.18 7.30° 7.41 7.53 8. 4 8.15 8.27 8.38 8.50 9. 1 9.12 9.22 9.34 9.46 10. 1 10.13 10.28 10.38 8 ” ” ” ” ” ” ” ” 2 ” ” 3 +b] ” ” ” ” ” 7.10 7.22 7.32 7.45 7.56 8. 7 8.18 8.30 8.41 8.53 9. 4 9.15 9.25 9.36 9.51 10. 3 10.18 10.30 10.42 » Absent 9 minutes, » » 8 ” » » 8 ” 2” 9 9 ” » » 8 ” » » 8 9 » » 8 ” ” 9 ” » » 8 ” ? ” 9 ” ”» 9 8 ” ” ” 8 ” ” ” ( ” » » 9 ” 29 29 10 ” 2 Eby 10 ” ” ” 10 9 ” ” 10 ” ” ” 8 ” 418 COMMUNICATION. 10.53 came tohoney; 10.56 away. Absent 11 minutes Li. 7 ‘ 11.11 eae ee 11.21 bs 11.25 ae ae 11.32 : ge se The wasp which came once yesterday returned ind rather disturbed the first. At 11.49 cametohoney; 11.50away. Absent 13 minutes. 11.57 s 12.0 ,, a as 12. 8 . 12.11 ,, tn pe Here I was away for about two hours. 2.42 came to honey; 2 - away. 2.58 53 >, Interval 12 minutes. 3.15 317 me. ee ee cas 3.25 0 3.28 5, » 8 » Here I was called away. 4.25 came to honey;4.28 ,, 4,41 : AAG op ye. ERO 5.15 i 5.19 ,, a’, Fae | sgh 5.30 i" 685 45 ea oy 5.45 5.50 4, ex. EO" ge 6. 2 ” 6.6 ” 12 ” 6.15 ‘ 620 4, a, 20. od This was the last visit that day. She made, there- fore, thirty-eight visits during the time she was watched, which was not quite eight hours. She was at work from 6.55 to 6.15; and assuming that she was occupied in the same manner during the three hours when she was not watched as during the rest of the time, she would have made over fifty visits to the honey during the day. Wishing, however, to have a complete record of a day’s work, I watched her the following day without intermission. COMMUNICATION. 419 September 21 ~-I began watching at ten minutes past six. 6.16 came to honey; 6.19 away. 6.29 6.41 6.55 7.11 7.23 7.37 7.56 8.11 came to honey; 8.14 away. 8.20 8.31 8.40 8.50 8.58 9. 8 9.18 9.30 9.39 9.50 10. 1 10.14 10.25 10.37 10.47 11. 0 11.17 11.34 11.50 12. 5 12.2C 12.36 1, 8 ” 3° ” ” ” 29 93 9 ” ” 2” 2” ” 29 29 9 ” ” EP ” ed 3 ” 99 ” eb) 33 ” 3” ” 6.32 6.44 7.0 7.15 7.26 7.42 8. 3 8.24 8.34 8.42 8.52 9. 0 9.11 9.22 9.32 9.40 9.54 10. 5 10.17 10.28 10.40 10.51 ll. 6 11.20 11.37 11.53 12. 8 12.24 12.40 1.11 ” ” ” ” 3° ” 2 ” ” 3 ” » ” ” ” 9 9 ” ” ” 99 ” ” 9 2” PE 99 PP 9 ” Interval 10 minutes. 9 ” ” ” ” 9 9 1] 11 8 11 14 ” ” ” ” 9 ” Was disturbed, and seemed rather troubled. Interval 8 minutes. ” 39 ” ” ” ” ” ” ” ” PP ” 99 9 ” ” ” ” ” ” ” ” 3 —_ WOTIODOMWONONOANWMODISH ” 33 ” ” ” ” 9 ” ”? ” 29 ” ” ” ” ” 2 ” ” 29 ” ” ” 420 COMMUNICATION. 1.26 came to honey ; 1.28 away. Interval 15 minutes 1.40 = 12 5 ee a. ge 1.57 : 2.2 4 oe: 2.10 e 2.13 4, a a 2.25 . 2.30 4, eS oe 2.45 Z 2.56 4, a. es She buzzed about at the other window for a few minutes, which made the interval longer than usual. 3.13 came to honey; 3.18 away. Interval 17 minutes, 3.29 ss 3.31 ,, 7 lls, 3.41 5 3.45 ,, 9 10_~—C#S 3.49 ” 3.52 > 2 4 ” 4. 2 9 4.6 5, ” 7 ” 4.19 9 4.22 ,, ” 13. Cs 4.29 3 4.33 ,, 3 ae 4.40 9 4.44 ,, ‘ i as 4.51 ss 4.53 4, 55 Ts 5. 4 a 5.6 4, 5 I 4, 5.16 ” 5.20 ” ” 10 ” 5.32 7 5.35 ,, is 12 (yy 5.45 Bs 5.50 ,, 5 10 It will be seen that the intervals of her absence were remarkably regular. On one occasion, indeed, she was only away four minutes; but this time I think she had been disturbed, and had not provided herself with a regular supply of food. The number of visits was fifty-one in eleven hours and a half. I tried whether she would be in any way affected by a dead wasp, so I put one on the honey; but she took no notice whatever. I observed with other wasps, that when the open window was not the shortest way to their nests, they had a great tendency to fly to that which was in the right direction, and to remain buzzing about there. INDUSTRY OF WASPS. 421 During the whole of this day only four or five strange wasps came to the honey. As regards the regularity of their visits, and the time occupied, other wasps which I observed agreed very closely with this one. For comparison, it may be worth while to give one or two other cases. I will commence with that of a worker,I believe V. vulgaris. observed on September 19. 10 a.M. I put her to the honey; she fed and then flew about the room, and at last got into my bee- hive. 10.54. She came in again at the window. I again put her to the honey. She again flew all about the room. 11.41. She returned, and this time came to the honey; but when she had fed again flew round and round the room, and did not seem able to find her way out. I therefore put her out. 12.11 she returned, and the same thing happened again. 12.28 ine } 12.31 flew straight away. 2 12.45 35 12.53 “ 12.57 4, 1.10 . 1.26 33 1.29 = 1.38 $s 1.41 » Interval 9 minutes 1.50 as Loo, os 2. 3 ” 2. 6 ” » 10 y 2.12 216 4, Be BEN ake Was disturbed. 2.20 = 2.25 4, a ae 2.40 - 243, eG 2.51 2.54 4, oe: 3. 1 ” 3.4 ” ” 7 ” 3.13 3.16 ,, ~ & 3.25 = 3.28, 9 422 REGULARITY OF VISITS, 3,35 \eetn back } 3.38 a \ Interval 7 minutes. to honey ; away 3.46 9 3.50 6 ee «BR Ss 3.58 os 4.1 3 re 8 yy 4.10 » 414 ,, » 9 » 4.23 ” 4.25 55 ee 4.34 ” 4.38 ” ” 9 ” 4.46 9 4.50 . oy. OB! ss 4.58 es 5. 4 ee so. BS 5.14 » Was disturbed and flewabout. 8 __,, She did not return any more that evening, but made her appearance again at half-past six the next morning. From twelve o’clock, when she had learnt her way, till five, she made twenty-five visits in five hours, or about five an hour, as in the previous cases. It struck me as curious that on the following day this wasp seemed by no means so sure of her way, but over and over again went to the closed window. Again, September 21, at 11.50 I fed a wasp. 11.56 she returned to honey; 11.57 flew away 12. 6 - is 12,8 gs 1.25 - si Hot 4 1.37 - s 139 4, 1.57 i. is 20° 55 2.15 ‘ 5 OAT 5 2.22 % ‘ 225 s, 2.32 ss ‘3 2.36 ,, 2.50 ” » 2.55 5 3. 2 . ‘ 3.4 4, 3.14 ‘s ‘3 BAS as 3.28 - ‘3 3.30 4, 3.40 . ‘3 3.44 4 3.51 . i 3.55 4. 4 35 . 4.8 , 4.16 4, . 4.20 ,, A DAY'S WORK. 493 ? she returned to honey; 4.31 flew away. 4,37 im J 4,41 i 4.46 S 4,48 - 4.57 is ” 5. 0 ri 5. 9 . 5 5.12 4 5.22 - 95 5.26 ” 5.31 C - 5.36 = She made therefore twenty-three journeys, but did not bring a single friend. The last case of which I will give particulars is the following, which has been already alluded to on p. 321. When I went to my sitting room at 4.13 a.m., I found her already there, though it was still almost dark. Her visits to the honey were as follows :— 4.13 a.m, returning at 4.32 ” ” ? 4.50 ” ” ” 5. 5 Pd ”» abd 5.15 ”? > ? 5.22 ” ”? ” 5.29 ” ”» ” 5.36 ” PP) ” 5.43 be) ”? ” 5.50 oP ” i ” 5.57 2 29 ” 6. 5 ” ” ” 6.14 39 2 ” 6.23 ” » ” 6.30 ” ”? ” 6.40 ” oe) ”» 6.48 ” ” ”? 6.56 ? ” ” 7. 5 PBd ” ” 7.12 ”? ” 2? 7.18 ” ” ”? 7.25 ” 2? ” 7.31 5, ” ” %40 4, ” ” 424 A DAY’S WORK. 7.46 a.M., returning at 7.52 8. 8.10 8.18 8.24 8.29 8.36 8.40 8.45 8.56 9. 7 9.14 9.20 9.26 9.37 9.43 9.50 9.57 10. 4 10.10 10.15 10.24 10.29 10.37 10.45 10.50 10.59 11. 6 11.15 11.22 11.30 11.35 11.47 11.55 12. 6 12.14 12,22 12.36 ” ”? PB) 2? ” ” ” ” ” ”? ” » ” ” Pd ” ” ” ”? ” 39 ” ” ” ” 7 ” ” ” ” ” 22 ” ” ” ” ” ” PP) 29 ” ” ” ”? ” ” Ped ” ” ” ” ” ” ” ” 29 A DAY’S WORK: 12.46 pP.m., returning at 12.52 12.56 — 14 1.11 1.20 1.25 1.30 1.35 1.43 1.48 1.53 2. 2.7 2.12 2.23 2.33 2.39 2.45 2.55 3. 2 3. 9 3.17 8.25 3.30 3.37 3.45 3.55 4. 5 4.12 4.19 4.28 4.39 4.46 4.56 5. 3 5.14 5.25 5.35 ” ” er) ” ” oP ” ” ” 445 426 A DAY’S WORK. 5.46 p.m, returning at 5.50 ” ood 9 6. 5 oy 9? ” 6.12 33 2 ” 6.20 ” ” ” 6.30 ” 2) ” 6.40 ? ” aed 6.46 ” ” oe 6.55 oP o ” 7. 7 ” ” ? TAZ 2° ” oe 7.30 » ” » 7.36 ,, » ” 7.46 ” oe ”? This was her last visit for the evening, and she thus made no less than 116 visits in the day, during which time only three other wasps found the honey, though it was lying exposed on a table at an open window. It will be seen that she worked with the utmost industry. No doubt, however, if a wasp is put to honey in an exposed place, other wasps gradually find their way to it. In the preceding experiments some few, though but few, did so. I then thought I would try a similar experiment with concealed honey. Accordingly, on September 20, I marked a wasp and put her to some honey, which she visited assiduously. The following morning I opened my window at 6, and she made her first visit at 6.27, the temperature being 61° Fahr. I then placed the honey in a box communicating with the outside by an india-rubber tube 6 inches long and i inch in diameter. The wasp, however, soon got. accus- tomed to it, and went in and out without much loss of time. The 22nd was finer; and when I opened my window at 6 in the morning, she was already waiting outside, the temperature being 61°. The 22rd was rather colder, and she came first at 6.20, the temperature being again 61°. I was not at home during these days ; but, as far as A DAY’S WORK. 427 I could judge from watching in the mornings and even- ings, no other wasp found the honey. On the 24th I had a holiday, and timed her as tollows. It was rather colder than the preceding days, and she did not come till 6.40, when the temperature was 58°. She returned as follows :— 6.49 8.19 6.58 8.26 7.12 8.35 7.22 8.45 7.32 8.52 7.40 9. 2 7.50 9.12 8. 0 9.45 8. 9 I had almost closed the window, so that she had a difficulty in finding her way. 9.58 10.32 10.10 10.51 The temperature was still only 60°, and it was rain- ing, scarcely any other wasps about. 11. 1 1.42 11.11 1.53 11.21 2. 0 11.29 2.11 11.40 2.26 11.46 2.35 11.56 2.51 12. 6 2.59 12.14 3. 8 12.25 3.14 12.33 3.23 1.21 3.32 1.32 3.40 428 DESCRIPTION OF 3.48 4.58 3.57 5. 6 4.12 5.17 4,20 5.28 4,29 5.35 4.39 5.42 4.47 5.52 This was her last visit. During the whole day no other wasp found the honey. I also tried other wasps, concealing the honey in the same manner, and with a similar result. I have no doubt some wasps would make even more journeys in a day than those recorded above. The following are descriptions of some new species referred to in the preceding pages. The first is the Australian honey ant. CAMPONOTUS INFLATUS, n. sp.’ Operaria.—Long. 15 mill. Nigra, tarsis pallidioribus ; subtiliter coriacea, setis cinereo-testaceis sparcis ; antennis tibiisque haud pilosis ; tarsis infra hirsutis ; mandibulis punctatis, hir- sutis, sexdentatis ; clypeo non carinato, antice integro ; petioli squama modice incrassata, antice convexa, pos- tice plana emarginata. Had. Australian. The colour is black, the feet being somewhat paler. The body is sparsely covered with stiff cinereo-testa- ceous hairs, especially on the lower and anterior part of the head, the mandibles, and the posterior edge of the thorax. The head and thorax are finely coriaceous. The antennz are of moderate length, twelve-jointed ; the scape about one-third as long as the terminal por- tion, and somewhat bent. At the apex of the scape are a few short spines, bifurcated at the point. At the apex of each of the succeeding segments are a few much less conspicuous spines, which decrease in size 1In the Linnean Journ. v. I have given figures of this species. THE AUSTRALIAN HONEY ANT. 429 from the basal segments outwards. The antenna is also thickly clothed with short hairs, and especially towards the apex with leaf-shaped sense hairs. The clypeus is rounded, with a slightly developed median lobe and a row of stiff hairs round the anterior bordcr ; it is not carinated. The mandibles have six teeth, those on one side be- ing rather more developed and more pointed than those on the other. They decrease pretty regularly from the outside inwards. The maxille are formed on the usual type. The maxillary palpi are six-jointed, the third segment Leing but slightly longer than the second, fourth, or fifth; while in Myrmecvcystus the third and fourth are greatly elongated. ‘The segments of the palpi have on the inner side a number of curious curved blunt hairs besides the usual shorter ones. The labial palpi are four-jointed. The eyés are ellip- tical and of moderate size. The ocelli are not developed. The thorax is arched, broadest in front, without any marked incision between the meso- and meta-notum ; the mesonotum itself is, when seen from above, very broadly oval, almost circular, rather broader in front and somewhat flattened behind. The legs are of mod- erate length, the hinder ones somewhat the longest. The scale or knot is heart-shaped, flat behind, slightly arched in front, and with a few stiff, slightly diverging hairs at the upper angles. The length is about two- thirds of an inch. The following refers to a new species of mite which I have found in nests of Lasius flavus, and of which Mr. Michael has been good enough to draw up the following description. URoPoDsa FORMICARIA, sp. Nov. This species, although it falls strictly within the ge- uus Uropoda, and not within Kramer’s genus Zrachy- notus as defined by that writer, still in most respects, except the very distinctions upon which the genus is 430 DESCRIPTION OF A MITE founded, resembles Zrachynotus pyriformis (Kramer) more closely than it does any other recorded species. It is, however, decidedly different, and is characterised by the squareness of its abdomen, the thickness and rough- ness of its chitinous dermal skeleton, and especially by the powerful chitinous ridges or wing-like expansions on the lateral surface between the second and third pair of legs. Length, and ?, about ‘95 millim. Breadth 24 Me BBD 22? The abdomen is almost square, but somewhat longer than broad, and slightly narrowed at its junction with the cephalothorax, from which it is not plainly dis- tinguished. The extreme edge is a strong chitinous ridge bordered with a thick fringe of short, stout, curved hairs, as in ZT. pyriformis. The dorsal surface of the cephalothorax is also narrowed towards the front, and has a curved anterior margin bent down so as to protect the mouth, as in that species ; it bears a few of the same kind of hairs as the abdomen, and has a chiti- nous thickening at each side. The abdomen rises almost perpendicularly from the marginal ridge. There is a central depression occupying the posterior half, or rather more than half of the abdomen ; and at the bottom of this depression are transverse ridges, the hinder ones nearly straight, and the auterior ones bent in the mid- dle, the central point being forward ; at the sides of, but not in, this depression, are two chitinous blocks which seem to form a starting-point for the ridges. Anterior _to this depression the central portion of the creature, i.¢. its longitudinal dorsal axis, is higher in level than in parts nearer the margin, and forms an irregular triangle of rough chitine. A broad chitinous plate or ridge pro- jects on each side above the second leg, and between that and the third, evidently for their protection ; it is probably flexible at the will of the creature, as in the genus Oribates. PARASITIC ON ANTS. 431 The sternal surface has strongly marked depressions for the reception of the legs. The coxe of the first pair of legs are largely developed, flattened, almost touch in the median line, and nearly conceal the mouth, as in the typical Uropodas. ‘The genital opening of the male is rather large, round, and placed centrally between the cox of the second pair of legs, The female appears only to be distinguished from the male by being more strongly chitinised, and by the conspicuous valval plate which occupies the whole space between the coxe of the oe and third pairs of legs and extends beyond both. The nymph is less square in the abdomen than the adult, and the border of hairs is absent ; the margin is somewhat undulated, the concave undulations being so placed as to give free action to the legs when raised ; the central depression of the abdomen is far less marked than in the adult ; a slight ridge runs all round the dorsal surface a little withia the margin; four ridges, two anterior and two posterior, run from the circumscribing ridge to a raised ellipse in the centre ; there are not any plates for the protection of the legs, and the coxe of the first pair are not flattened as in the adult. This mite lives in the nests of Formica flava. Description of a New Genus and Species of Phoride parasitic on Ants. By G. H. Verratt, Esq., Memb. Entom. Soe. Sir Joun Lussock has kindly forwarded for my exami- nation and determination certain specimens of dipterous insects said to have been found parasitic on species of ants, which latter he has been studying with care as to their habits. Having given considerable attention to the family Phoride, I was agreeably surprised to find 439 DESCRIPTION OF TWO NEW the parasitic specimens to be forms new to science. One of these is a new species of the genus Phora ; the other I regard as possessing characters sui generis, and hence define it under the generic title Platyphora, at the same time bestowing on the species the name of the discoverer, who worthily pursues entomological researches, spite of many pressing public engage- ments. The subjoined descriptions embrace the diagnostic peculiarities of the insects in question. PHoRA FORMICARUM, n. sp.—Nigro-cinerea, fronte setosa, caniculata ; antennis mediocribus, cinereis; pal- pis magnis, flavis; halteribus flavidis; pedibus totis pallide flavis, inermibus, tibiis intermediis unicalcara- tis, posticis modice dilatatis ; alis subhyalinis, nervo secundo simplici, nervulis vix undulatis. Long. vix $ lin. Frons broad, grey, bristly, two large bristles being close to the eye-margin ; down the centre is a deep im- pressed channel, which at its lower end joins a channel above the antenn, and at its upper end a channel round the raised vertical triangle; the space between these two latter channels (comprising the true frons) is about once and a half broader than deep; on the vertical triangle are two bristles; the third joint of the an- tenn is moderately large, ovate, grey ; the arista short, somewhat yellowish, almost naked; the palpi con- spicuous, all pale yellow, with a few short black bris- tles at the tip; on the cheeks are some short black bristles. The thorax is grey or brownish grey, broad, not much arched, the disk being nearly flat, and on the hinder part absolutely concave ; on the disk there are no long bristles, but a dense clothing of rather short black bristles ; along the side of the thorax between the humeri, the base of the wing, and the scutellum are some long black bristles, and two on the thorax just before the scutellum ; on each side of the scutellum are FLIES PARASITIC ON ANTS, 433 two long bristles ; halteres dirty pale yellow ; abdomen bare, dull black, with slightly yellowish incisures ; ovi- positor polished black, long, slightly incurved and grooved. Legs pale yellow, including the coxa, clothed with minute black bristles; all the coxz with two or three black bristles at the tips, the legs otherwise bare except- ing the spurs; femora flattened and widened, especial- ly the hind pair, the hind tibize also slightly flattened and widened on the apical half; middle tibie with a long spur inside at the tip, and hind tibiwe with a small one inside and a very minute one outside ; tarsi longer than the tibiz, joints gradually diminishing in length. Wings very slightly smoky, broad; second thick vein not extending half the length of the wing, thick- ened, but not forked at its tip; first veinlet with a steady curve ; second very slightly curved at base, other- wise straight; third very slightly undulated ; fourth hardly visible at base, evident towards tip, very slightly undulated ; vosta bristly up to end of second thick vein. This species is readily distinguished by its simple second thick vein, channelled frons, small size, and by the absence of bristles on the tibie. It is parasitic on Lasius niger. PLATYPHORA, n. gen. Lata, planx, tota absque setis. Frons latissima. Thorax transversus. Abdomen parvus. Alarum vena cubitalis simplex, subacostali parallela ; venule undu- late ; costa ad basin subciliata. Distinguished from all the existing genera of Pho- ride by its flat and broad shape, which resembles that of the small species of Sphuerocera. The ab- sence of strong bristles on the frons, thorax, and legs also distinguishes it from all the genera except Gym- nophora, which, however, is of the usual arched Pho: 434 PLATYPHORA LUBBOCKII. ra-shape, and has the cubital vein forked, costa bare, &e. Puatyrnora Luszocxu.—Nigra, nitida ; abdomine triangulari, segmento tertio parvo ; femoribus posticis basi flavidis ; alis apice latis, flavido-hyalinis, costa ad basin subciliata, vena cubitali ad medium cost ex- tensa subcostali parallela, venulis undulatis. Long. ? lin. Broad, flat, shining; frons very broad, the eyes scarcely occupying each one-sixth the width of the head; it is moderately shining, gently arched, and pretty densely clothed with minute bristles ; the three ocelli visible slightly luteous ; antenne with the third joint rather large, somewhat rounded ; thorax broad, flat, rather broader than the head, angles tolerably rounded, disk shining (in appearance suggesting a small Spherocera), beset with very minute bristles, which be- come rather scarcer towards the hinder part ; scutellum rather dull, margined, nearly four times as broad as long: abdomen black, narrower and shorter than the thorax (again suggestive of Spherocera) ; each segment after the second successively narrower, the last one be- ing almost triangular; the third segment is very short, contracted under the second ; the hind margins form a curved convex towards the thorax, the first segment be- ing slightly emarginate in the middle; the sixth (last) is much the longest. Legs stoutish, blackish, basal two- thirds of hind femora yellowish ; middle tibie with two small spines at the tip. Wings considerably over- lapping the abdomen, yellowish hyaline, darker about the basal half of the costa, blunt at the tip, cubital vein extending about half the length of the wing, and the costa slightly ciliate up to its end, subcostal vein run- ning parallel to it and ending just before it ; both veins a little thickened at their ends ; first veinlet curved S- like, considerably at its base, slightly at its end, vanish- ing distinctly before the tip of the wing ; second veinlet also S-like, diverging at its end from the first, and end- ing distinctly below the tip of the wing; third veinlet . PLATYPHORA LUB3OCKIL 435 slightly undulated, ending very wide from the second ; fourth faint, not reaching the end of the wing. This description having been made from a specimen gummed down on card, though in very good condition, I am unable to decide on the sex, or to examine the face, palpi, base of antennz, or coxe. INDEX. ABD { BDOMEN of ant described, 10, (\ 13; of the Mexican honey ant, 19, 47 Acucia with ho!low thorns in- habited by ants, 57 Affection less powerful than hatred among ants, 106 ; absence of, among bees, 286 Agricultural ants, 6], 92 Aldrovandus quoted as to ants, 61 Amazon ants, see Polyergus ru- Sescens Amber, an intermediate form of ant preserved in, 68 Analogies between ant societies and human, 91 André quoted as to Platyarthrus, 75; as to the slaves of F, san- guinea, 80 Anergates, 85 ; no workers among them, 86; degraded condition of, 89 Animal food, queens hatched in an artificial nest supplied with, 40 A ugrecum sesquipedale, length of dowers of, 52 dnomma arcens, the Driver ant, described, 20, 63; their blind- ness, 65 Ants, three families of, 1; four perioils «f life in, 65 duration of life among, 8, 38, 40; structure AFH of, 10; different classes of indi. viduals ainong, 18 ; communities of, 24; games of, 28; their rela- tion to plants, 50; often insecti- vorous, 59; their relations to other animals generally hostile, 63; their enemies, 26, 67; their domestic animals, 67-78; pro- gress among, 90; their beha- viour towards each other, 94, &c.; mental powers of, 181; tieir sense of vision, 11, 182- 220, 258; of smell, 127, 238, 258; of hearing, 221, 226; stri- dulating apparatus among, 230 their intelligence, 236 ‘Ant eggs,’ 7 ‘ Ant-rice,’ 61 Antenna of ant described, 10; serse organ in terminal portion of, illustrated, 227 Antenne as means of communica tion among ants, 153; as organs of hearing, 221, 226; of smell, 94, 234 Antirrhinum fertilised by humble bees, 54 Aphides made use of by ants, 25, 67 ; different species of, utilised by different ants, 68; thei honey, 69; their eggs tended by ants, 70; not aomesticated by F. fusca, 91 £38 ARI Aristida oligantha, ‘ant-rice,’ 61 Artificial nests for ants, 3, 164 Ateuchus pilularius, anecdote of, 154 Atrophy of the imaginal discs of the ant-workers, 12; of the sting in Wormica, 165; of the eyesof Platyarthrus and Bechia, 15 Atta barbara, the eye in, 113 variety of workers among, 19 — structor, its treatment of col- lected grain, 61 -— testaceo-pilosa, experiment with, as to power of communication, 177 Attachment among ants, 94 Auditory organs, structures in ant- antennz probably serve as, 226 Australian honey ant, 49; de- scribed, 428 ATES, Mr., quoted as to the tive kinds of workers in Saiiba, 22; as to ant-play, 29; as to the use made by ants of leaves, 57; as to the armies of Eciton, 65; as to leaf-cutting by Satiba, 237 Batrisus, rarely more than one specimen of, found in an ants’ nest, 78 Beckia, one of the ant-guests, 74 Bees, occasional fertility of workers among, 36; means of recognition among, 126; their sense of hearing, 221, 290; ob- servations with, 274; difficulty in finding their way, 278; their behaviour in a strange hive, 281; their recklessness, 285; their want of mutual affection, 286; ‘heir influence on the develop- ment of flowers, 61, 29. , their colour sense, 291; their prefer- ence for blue, 294-310; experi- ments on communication among them, 276, 401 INDEX. CAR Beetles kept in ants’ nests, 74, 76, 90 Belt, Mr. Thomas, quoted as to floral defences against ants, 51; as to defence against leaf-cut- ting ants, 57; on the raids of Eeiton, 66; on an _ ant-like spider, 66 Bert, Prof, Paul, as to the limits of vision, 219 Bichromate of potash, experiments with, 211 Bisulphide of carbon, experiments with, 208 ; Blanchard, M., quoted as to the origin of nests, 30 Blindness of Anomma and Eeiton 65 ; of Platyarthrus and Beckia. 75 Blue, the favourite colour of hees, 294, 304, 310; flowers, their late origin, 308 Bonnet, M., on aphis eggs, 70 Bonnier, M., on indifference to colour among bees, 302 Bothriomyrmez meridionalis, the eye in, 11 Brazil, blind hunting ants of, 65; use made by the Indians in, of the tenacity of an ant-bite, 96 Buchle dactyloides, seed of, col- lected by ants, 61 Biichner, Dr., as to Texan harvest- ing ants, 62 Burmeister, on the power of recog- nition among insects, 126 Butterfly, ants seen licking the larva of, 68 C4uPonorus inflatus, de scribed, 428 -- ligniperdus, the eye in, 11, communication among 158 Captivity, mode of keeping ants in, 2,3; a wasp in, 315 Caterpillars killed by ants, 59, 66 Caryophyllacee, correlation of form and colour in, 309 INDEX. CHE vhennium, rarely more than one specimen of, in an ants’ nest, 78 Christ, M., on the length of life of queen ants, 9; on ant roads, 25 Chrome alum, experiments as to ant vision with, 217 Chromium chloride, experiments with, 217 Olaparéde, M, as to insect-vision, 183 Clark, Rev. Hamlet, as to an ant- tunnel in S. America, 25 Claviger,a blind beetle, a guest in ants’ nests, 75, 76; experi- ments with, by M. Lespés, 90 Cleanliness of ants, 29 Coccida, their use to ants, 68 Cocoons spun by some larve of ants, 7 Colobopsis truncata and C. fusipes, two forms of the same species, 20 Colour-sense of ants, 186, &c.; of bees, 291, &c.; of wasps, 316; less developed among wasps than bees, 321 Colours of flowers, evolution of, 308 Communication, power of, among ants, 153, &c.; among bees, 156; experiments as to, with ants, 160, 344, 376; with bees, 276, 401; with wasps, 311, 415 Communities of ants, 24; power of mutual recognition among members of, 119, 333 Compassion among ants, instances of, 106, 108; absence of, among bees, 286 Oo-operation, experiments as to, among ants, 365-376 ‘orrelation of form of knot with stinging power in ants, 13; of colour in flowers with specialisa- tion of form, 308 vourage of ants, 27; of wasps, 314 trematogaster lineolata, adoption of a queen by, 34 439 DUI Crematogaster seutellaris, their neglect of friends in trouble, 98; experiments as to percep- tion of colour among, 192 — sordidula, threatening attitude of, 16 Cross-fertilisation effected by in- sects, 50 DAPHaIA, limits of vision in, 219 Darkness, education of young ants conducted in, 5; effect of, on the eyes of Platyarthrus and Bechia, 75 Darwin, on the sound produced by Mutilla, 229 — Francis, on the use of the leaf- cups of teazle, 52 Dead, treatment of the, among bees, 287 Defences of flowers against un- bidden guests, 52-7 Degradation of Stvongylognathus, 85; caused by slaveholding, 89 Dewitz, Dr., on the non-develop- ment of the sting in the For- micide, 14; on eggs laid by fertile workers, 36, 40 Dinarda dentata in ants’ nests, 76, 77 Dipsacus sylvestris, leaf-cups of, 52 Direction, sense of, among ants, 260; guided by the position of the light, 268; sense of, among bees, 278; among wasps, 321 420 Discs, atrophy of imaginal, in worker ants, 12; cleared by harvesting ants, 61; experi- ments as to sense of direction with rotating, 261, &c. Division of labour among ants, 23, 44; tabular view of experi- ments on, 324 Domestic animals of ants, 68-78 Driver ants, see Anomma arcent Dujardin, M., as to the power of 44C INDEX, EBR communica‘ion among bees, 156, 313 , BRARD, M., his observations as to the origin of ants’ nests, 31 Eciton, the eye in, 11 — drepanophora, their order in marching, 21 — erratica, soldiers among, 21; their covered galleries, 65 — legionis at play, 29 — vastator, soldiers among, 21; their covered galleries, 65 Economy of labour among ants, experiments as to, 240, &c. Eggs of ants described, 6; laid occasionally by worker ants, 35 ; by worker bees and wasps, 36 ; these always produce males, 37 ; as to dijerence of sex in, 40; of aphis, tended by ants, 69; and hatched in captivity, 71 Electric light, experiments on ants with, 200 Emery’s observationson Colobopsis, 20 Enemies of ants, 26, 67 Evolution of colour in flowers, 308 Experiments, as to the adoption of a queen by ants, 32; as to di- vision of labour among ants, 23, 44, 324; as to their care of aphis-eggs, 70; on Claviger, 90; as to the treatment by ants of injured companions, 94, 107; with chloroformed ants, 98, 108-111; with drowned ants, %9; with buried an's, 102; as to treatment of stranger ants, 1.£, 119, 124 333; as to mode of recognition, 108; with in- toxicated ants, 111 118; as to power of recognition among ants, 119, 333 ; and among bees, 126; with ant-pupz removed from nest, 129-147; on sister- ants brought up separately, 147- FOO 152, as to power of communi cation among ants, 160-181, 344-376 ; among bees, 274, 401; among wasps, 311, 415; as to perception of colour, 186; with coloured solutions, 194; with spectrum, 198 ; with the electric light, 201; as to ultra-violet rays, 200-220; with magnesium spark, 207 ; as to sense of hear- iug among ants, 222; among bees, 290; as to sense of smell among ants, 233, 258; among bees, 288 ; as to ant intelligence, 237; as to economy of labour, 241; as to ingenuity among ants, 243-6; as to their power of finding their way, 250; as to means of tracking. 168, 383, 387; as to sense of direction among ants, 260; among bees, 278; and among wasps, 321 ; as to guidance of ants by sight, 266; as to the belkav‘our of bees in a strange hive, 281; as to their compassion, 286 ; as to their colour sense, 291; and their preference of certain colours, 302; as to colour sense among wasps, 316 Expulsion of ant from nest, 98 Eyes of two kinds in ants, 10; compound, 182; various de- velopments of, 183 IACETS of the eye in ants, number of, 11; described, 182 Feeding, loss of instinct of, 76, 83, 87 Fertilisa‘ion of plants by insects, 50, 291 Fighting among ants, different modes of, 17 Flowers, their defences against unprofitatle insects, 51-55; in- tluence of bees on their develop- ment, 291; paucity of blue, 3U8 Food of ants, 25, 63; its effect in INDEX, 441 FOR determining the sex in ants and bees, 40; individual ants in certain species serve as recep- tacles of, 47 Foragers, certain ants of a nest told off as, 45, 47 Forel, Dr., referred to as to the emergence of pupz of ants, 8; as to their compound eyes, 10; as to the position of spiracles, 14; as to the offices of young ants, 23; asto F. rufa, 27; as to ant-games, 28, 29; as to origin of nests. 31; as to eggs laid by workers, 35; on the honey ant, 40; on the germina- tion of grain in ant-stores, 61; as to beetles in ant nests, 78; as to the slaves of F. sanguinea, 80; as to the slave-making of Strongylognathus, 85; on Aner- gates, 86; on the behaviour of ants to each other, 94; on re- cognition among ants, 120; as to power of communication among ants, 158; as to their insensibibility to sound, 221 ; as to special organs in their an- tenn, 227 7 Formica bispinosa, its nest, 24 — cinerea, 16; character of, 27; eggs laid by workers among, 37, 39; duration of life of, 42 — congerens, Thiasophila in nests of, 77 — exsecta, mode of attack of, 17; extent of nest of, 24; Thiaso- phila in nests of, 77 — flava, Uropoda in nests of, 431 = fusca, occasionally spins a cocoon, 7; its timidity, 27; in- troduction of a queen among, 84; ergs laid by workers among, 38, 39; queens produced in captivity, 40; longevity of, 42; division of labour among, 45; occasionally found’ in the nests of F. rua, 79; enslaved by FL sanguinea, 80; Platy- 30 FOR arthrus received in nests of, 90; their condition analogous to that of the hunting races of men, 91; their neglect of friewlz in trouble, 96; expulsion of a member from the nest, 98; mite aitached to the head of a queen of, 98; their neglect of im- prisoned companions, 103 ; hos- tility towards imprisoned strangers, 104; instances of their kindness to crippled com- panions, 106; experiments as to recognition among, 122, 130, 134, 233; on power of commu- nication among, 161, 180; as to perception of colour among, 188, 193, 201 Formica gagates enslaved by F. sanguinea, 80 — ligniperda, experiments as to sense of hearing among, 223 ; as to sense of smell among, 234 — nigra, experiment as to power of communication among, 363 — pratensis, eye of, 10, 184; at- tacked by #. exsecta, 18; its treatment of slain enemies, 27; Stenamma in nests of, 78; large communities of, 119 — rufa, its power of ejecting poi- son, 15; its mode of attack, 17, 27; nests of, 23; large number of insects kept in nests of, 74, 75; Stenamma in nests of, 78 — rufibarbis perhaps a variety of F. fusca, 80 — sangwinea, its mode of attack, 17; duration of life of, 41, 42; Dinarda in nests of, 77; their periodical attack on neighbour- ing nests, 79; slaves made by, 80; not yet degraded by slave holding, 88; they apparently understand the signals of Pra- tensis, 159 Formicidae, one of the three fami- lies of ants, 1; power of sting: ing absent in them, 13 442 FRA Frank.jn, Dr, as te power of com- munication among ants, 155 Friends, behaviour of ants to, 97, 101; recognition of, 119, 333 (j ALLERIES, covered, made by Eciton, 65 Galton, Mr. Francis, on domestic animals kept as pets, 77 Games among ants, 28 Gélieu, M., on means of recogni- tion among bees, 126 Gentians, colours of, 310 Glasses, experiments on ants with coloured, 186, &c. Gould, Mr., on the emergence of the imago, 8; on ant-games, 28; on the eggs of aphides, 69 Goureau, M., on the sound pro- duced by Mutilla, 229 Graber, Dr. von, on the sense organs in the legs of Gryllus, 231 Grain collected and stored by ants, 26,60; germination of, prevented by ants, 61 Gredler, Dr., anecdote of ant-intel- ligence told by, 237 Grimm’s observations on Dinarda, 76 Grote, Mr., quoted as to the ne- cessity of morality in societies, 93 Growth of insects takes place during the larval stage, 8 Guests of ants, 74 Gryllus,sense organs in tibise of,231 | ABITATIONS of ants, 24 Hagens, von, quoted as to myrmecophilous beetles, 77; on the slave-making of Strongy- lagnathus, 85 ; on Anergates, 86; his suggestions as to Strongy- dognathus, 87 Hairs of plants as defences against insects, 55 Harvesting ants, —9, 92; in the South ot Europe and Texas, 61 INDEX. INS Hatred a stronger passion with ants than affection, 106 Head of ant described, 10; large size of, in workers of certain species, 20, 22 Hearing, sense of, among irsects, 221; possibly present in ants, 226; among bees, 290; among wasps, 313 Heterius sesquicornis, nests, 77 Hicks, Dr. J. Braxton, on the antenne of insects, 227 Hildebrand on the variations of blue flowers, 310 Honey, love of ants for, 51; of aphis, 69; experiments on ants entangled in, 98 / Honey ants, 19, 47 ; independently originated in Mexico and Texas, 49; of Australia described, 428 Hope, Mr., quoted as to harvest- ing ants, 60 Horse ant, see F. rufa Huber, as to ants playing, 28; as to the formation of a nest, 30; on the care taken by ants of aphis eggs, 70; as to slavery among ants, 81; as to their re- cognition of friends, 120; as to their deafness, 221 Hunting ants, 59, 63, 91 Hydnophytum formicarum, its 4s- sociation with ants, 68 Hymenoptera, common origin of the sting in the, 15; the social, means of communication be tween, 153 in ants’ NDIVIDUAL differences be- tween ants, 95, 101; between bees, 279 Indusiry of ants, 27: of wasps, 321, 421 Insects, their metamorphoses, 8; their agency in fertilisation of flowers, 50, 291; mimicking ante, 66; kept by ants, 73; recogni- tion among, 126; their vision, INDEX. INg 182; their hearing, 221; pos- sibly possess seuses inconceiva- ble to ourselves, 225 fnsensible ants, experiments with, 99-108 Intelligence among ants, 181, 236; experiments as to, 240 ‘ntoxicated ants, experiments on, 111; tabular view of experi- ments, 118; experiments re- ferred to, 128 ERNER on floral defences, 52 ; on the uses of nectaries, 56 Knot in ants, specific characters offered by forra of, 13 Kirby and Spence, Messrs., as to power of communication among ants, 156 ; on the power of sound in Mutilla, 229 ABOUR, division of, among i ants, 23, 44; experiments as to economising, 240; tabular view of experiments on, 324-332 Landois, on the sound emitted by Mutilla, 229; on stridulating ap- paratus in ants, 230 Laagstroth, Dr., as to recognition by smell among bees, 281; on their recklessness, 285 Larve of ants described, 6; of stranger nests carefully tended. 129 Casius brunneus prefers the aphides of the bark of trees, 68 — flarus, period of larval life in, 7; the eye in, 11; will not adopt a strange queen, 32 ; mites in the nest of, 67; keeps flocks of the root-feeding aphis, 68 ; keeps four or five species of aphis in i's nests, 73; Platy- arthrus a guest of, 75, 90; they have arrived at the ‘pastoral stage’ of progress, 91; their behaviour to a dead queen, 108; to chloroformed friends and strangers, 108-111; to intoxi- 443 LEP cated friends and strangers, 111; their treatment of strangers, 123; perception of colour among. 190, 193, 195; experiments a to sense of hearing among, 228 ; stridulating apparatus in, 231; structure in tibia of, 232; want of ingenuity among, 248 ; earth- works constructed by, 249; ex- periments with, as to power of communication, 365; as to co- operation, 372; new species of mite found in nests of, 429 Lasius niger, workers among, 19; fed by aphides, 25; eggs laid by workers among, 37; longe- vity of, 42; typical nest. of, illus- trated, 42; and described, 44; they carry seeds of violet into their nests, 59; their choice among aphides, 68; Piaty- arthrus a guest of, 75; Heterius found in nests of, 77; experi- ments as to Claviger in nests of, 90; observations on a wounded worker among, 95; experiments with buried individuals of, 102; with pupe as to recognition among, 131; as to power of communication among, 160, 163, 172, 175, 356-362, 377; as to perception of colour among, 191, 201; as to their intelligence, 240; their want of ingenuity, 242, 246; as to scent, 258; as to sense of direction among, 260; Phora formicarum para- sitic on, 433 — Juliginesus, the eye in, 11; stridulating apparatus in, 230 Latreille quoted as to compassion shown by ants, 94 Leaf-cutting ants, 57 Legs of ants described, 12 Leptothsrax acervorum, Platy- arthrus a guest of, 75; Temo- gnathus in nests of, 87 note — muscorum, Tomognathua io nests of, 87 note 144 LES Lespés, M., on eggs laid by work- ers, 35; on grain stored by ants, 61; on the feeding of Zome- chusa by ants, 76; on ‘the domestic arimals of ants, 90 Leuckart, his experiments on ant- intelligence, 238 Life, duration of, among ants, 8 Tight, dislike of ants to, 2, 186; as aid to sense of direction among ants, 268; bees attracted by, 284 Ligurian queen bee, introduction of a, 287 Limits of vision with ants, experi- ments as to, 199-206; in Daph- nia, 219 Lincecum, Dr., as to Texan har- vesting ants, 62 Linnzeus quoted as to aphides, 67 Locust, ants apparently deceived by a leaf-like, 66 Lomechusa fed by ants, 76 Long, Col., as to the sense of hearing among certain ants, 226 Longevity of workers of Zasius niger, 38, 42; of queen ants, 9, 40 Lowne, Mr., quoted as to the func- tions of ocelli, 183 Lund, M., quoted as to the intel- ligence of ants, 236 Lycena pseudargiolus, ants seen licking the larva of, 68 CCOOK, Mr., quoted as to the adoption of a queen by Crematogaster, 34 ; as to honey- ants, 48; as to the grain-fields of the Texan harvesting ant, 62; as to ants licking the larva of a butterfly, 68; on recognition by smell among ants, 127 Markel quoted as to insects kept by F. rufa, 74 Maizaonides as to the ownership of ant-stores of grain, 59 Males only produced by eggs laid oy workers among bees, wasps, end ants, 36, 37; of Axergates INDEX. MYR wingless, 86; of Tomognathus wingless, 87 note Mandibles of ants, 11; pointed ir Polyergus. 18; but toothless 82; sabre-like in 8. Hubert, 84 Marking ants, bees, and wasps methods of, 5 Meer Hassan Ali, as to harvesting ants, 60 Mental powers of ants differ from those of men in degree rather than in kind, 181 Metamorphoses undergone by in- sects, 8 ‘Metamorphoses of quoted, 30 Mexico, honey-pot ants in, 19, 47 Michael, Mr., description of U7o- poda by, 429 Microphone, experiment with, 225 Mimicry, protective, instances of, 66 Insects, Mischna, rules in, respecting ant- hoards of grain, 59 Mites, ants infésted by, 26, 98; new species in nests of Lasius flavus, 429 Mocquerys, M., on the tenacity of the bite of the ant, 96 Mogeridge, Mr., on harvesting ants, 61 Morality among ants, question as to, 93; among bees, 285 Mosaic theory of the vision of com- pound eyes, 184 Moseley, Mr. H. N., quoted as to the connection between ants and certain epiphytes, 58 Mouth of ant described, 11 Miiller, his observations on Cla. viger, 76; on the mosaic theory of vision, 184; on the colouw sense in bees, 307; on blue flowers, 310 Mushrooms grown by ants, 57 Myrmecina Latreillii, the eye in, 11; their mode of defence, 16; said to be phlegmatic in disposi tion, 27 INDEX. MYR Myrmecocystus mexicanus, honey- holding individuals among, 19; foragers bring supplies of honey to them, 47 Vyrmecodia armata, its associa- tion with ants, 538 Vyrmecophilous insects, 68- 78 NMyrmica ruginodis, period of Jar- val life in, 7; length of tife of males of, 9; origin of a nest of, 82; observations on a wounded specimen of, 96; experiments as to recognition among, 121; as to communication among. 164, 348; illustration of terminal portion of antenna of, 227; sense-organ in tibia of, 233; their unwillingness to face a fall, 245 — scabrinodis, cowardly nature of, 27; Platyarthrus a guest of, 75 Myrmicida, one of the three fa- milies of ants, 1; correlation of form of knot with power of sti.,ing in the, 13 ECTARIES, uses of, 56 Nests for ants, artificial, de- scribed, 3, 164; ofants classified and described, 23, &c.; three modes of formation. of, sug- gested, 30; of Lasius niger de- scribed and illustrated, 42 Neuters among ants, preduction of different forms of, 22 Normann, M. de, honey ants brought from Mexico by, 47 (CELTS, or simple eye in ants, 10; absent in the work- ers of some species, 11; origin of, 182 Wer lema cephalotes, the Saiiba ant, five kinds of individuals among, 21; extent of nest of, 24; leaf-cutting among, 237; intelligence of, 239 445 PoG Qeophylia, sting in, 13 Organ of sense in antenna of ant, 226; in tibia of Gryllus, 231; in tibia of ant, 232 Ormerod, Mr., as to the sense of - hearing among wasps, 221 Ova of aphis described, 71 note ARASITES of ants, 26, 67, 74, 431, 433; of bees, 26 Pass-word, experiments as_ to, among ants, 108; supposed use of, among bees and ants, 126; experiments as to, with pups, 129; existence of, apparently disproved, 147 Pets, domestic animals kept as, by savages, 77 Phases of life among men and ants, analogy between, 91 Pheidole megacephala, pugnacity of small workers of, 20; experi- ment as to power vf communi- cation among, 180; sense-organ in tibia of, 233 — pallidula, the eye in, 11; com- munication among, 158 -- providens, its s'orage of grass seeds, 60 Phora formicarum, its attacks on ants, 26, 74; described, 432 Phoridz parasitic on ants, 67, 74; new genus and species of, 431 Pigs kept as pets by savages, 77 Plagiolepis pygmea, the eye in, 11 Plants, relation of ants to, 50; their different modes of defence against unprofitable insects, 51; benefited by the action of in sectivorous ants, 59 2 Plato, epigram by, quoted, 185 Platyarthrus Hoffmanseggii,aguest of the ants, 75; experiments with, 90 Platyphora Lubbochii,67; described 434 Pogonomyrmex barbatus, stores ‘ant-rice,’ 61 446 Pot Peison ejected oy Formica rufa, 15 Polistes, robbery among, 286; P. gallica, a specimen of, kept for nine months, 315 Polyergus rufescens, the eye in, 11; its mode of combat, 18; indi- vidual courage of, 27; males produced from eggs laid by workers among, 39, 45: greatly dependent.on its slaves, 80, 83; slave-making expedition of, de- scribed, 81; degrading effect of slave-holding on, 89; imprisoned friends and strangers equally neglected, 105; power of com- _ munication among, 158, 180 Polygonum amphibium, glandular hairs absent from specimens growing in water, 56 Ponera contracta, the eye in, 11 Ponerida, one of the three families of ants, 1; form of knot in, 13; stridulating apparatus in, 230 Primulace@, evolution of colour in, 809 Protective mimicry, 66 Pupz of ants, 7; experimented on as to power of recognition among ants, 129 Python said to have been de- stroyed by the Driver ants, 64 UEEN ants, longevity of, 9, 41; their wings, 12; several in a nest, 19; reluctance of ants to adopt a new, 32; never pro- duced from workers’ eggs, 36; seldom produced in captivity, 40; treatment of a dead, 108 Queen bees, limited nature of de- votion of subjects to, 287 ANUNCULACE, correla- tion of colour with speciali- sation of form in, 308 Recognition of friends by ants, experiments on, 108, &c., 119, INDEX. SIE &c.; after long separation, 123 233, 333 ; means of, 125 ; among bees, 126; experiments as to, with pup,129-147 ; as to sister ants brought up separately, 147 ; proved to be communal, not per- sonal, 152 Relations, behaviour of ants to, 93 Retrogression of organs: of sting, 14; of wings, 15; of eyes, 75 Roads made by ants, 25 Robbery among bees, 285 Rufescent ants on a slave-making expedition, 81 St FARGEAU, Lepeletier de, \) on the origin of ants’ nests, 31; on the benevolence of ants, 94; as to hearing among insects, 221 Saiiba ant, see @codoma cephalotes Sauvages, Abbé Boisier de, on the connection between ants and aphides, 68 Savage, Rev. T. §., ‘ On the Habits of Driver Ants,’ quoted, 20, 63, 64 Scavengers, some ant-guests may serve as, 75 Scent, power among ants of track- ing by, 124, 171; experiments with different kinds of, 233; importance of, to ants, 258 Schenk, Anergates discovered Ly, 86 Sceretion of aphis retained till re- quired by ants, 69; of Clawiger and Dinarda as food for ants 75, 76 Seeds of violet collected by arits, 26; stored by ants, 60; anc prevented from sprouting, 6) Senses of ants, 182; organs of, 226, 232 Sentinels among bees, 288 Sex of eggs determined by treat- ment, 40, 41 Siebold, von. on sense-organs in INDEX. SIG Gryllus, 231; on robbery among Polistes, 286 Sight, how far ants are guided by, 251, 258, 266, 270 Signals given by ants, 158 3lave-holding, structural changes induced by, 82; degradation caused by, 89 Slave-making ants, 18 ; expedition of, 81 Slavery among ants, origin of, 79; degrading tendency of, 82-89 Smell of Myrmecina possibly pro- tective, 17; on recognition among ants by, 127; sense of, among ants, 233; the probable means of recognition among bees, 281 ; sense of, keen among bees, 288 Snake killed by Driver ants, 64 Soldiers among ants, 20; those of Saiiba do not fight, 22; their origin, 22 Solenopsis fugaz, the eye in, 11; the enemy of its hosts, 78 Solomon on the foresight of the ant, 59, 60 Sound, apparent insensibility of ants to, 222; possible existence of, beyond human auditory range, 223, 233; how produced by Mutilla, 229; apparent in- sensibility of bees to, 290 Specialisation of form in flowers correlated with colour, 308 Spectrum, experiments as to per- ception of, by ants, 198 spiders, their intelligence in es- caping the Ecitons, 66 ; mimick- ing ants, 66 Spiracles of ant, position of, 12, 14 Stenamma Woedwardii, the eye in, 11; found exclusively in nests of Formica, 78 3tethoscope-like organs in antenna of ant, 228 Sting in ants, possible correlation of, with form of knot, 13; pro- bable common origin of, in ants, 447 . TYN bees, and wasps, 14; atropkied condition of, in Formica, 15; the loss of, fatal to bees, 283 Strangers, behaviour of -ants to- wards, 104, 109, 119, 333 Stridulating apparatus in Mutilca, 229; in ants, 230 Strongylognathus Huberi, its mode of slave-making, 84 — testaceus, the eye in, 11; s'ave- holders in spite of their feedle- ness, 84; their degradation, 87, 89 Sulphate of quinine, experiment with, as to ant vision, 216 Surgical use of ant heads in Bra zil, 96 Sykes, Mr., quoted as to seed- collecting ants, 60 ‘AME wasp, behaviour of 3, 315 Tapinoma, length of period of larval life in, 7 — erraticum, the eye in, 11; sheir agility, 24; Heterius in nests of, 77 Teazle, possible uses of leaf-cup in, 52 Letramorium cespitum, the eye in, 1L; feigns death as a defence, 17; alleged greediness of, 27; enslaved by Strongylognathus, 84; entire dependence of Aner. gates upon, 85 Texas, harvesting ants in, 61 Thiasophila angulata in ants’ nests, W7 Thorax of ant described, 12 Tibia of Gryllus, sense organ in, 231; of Lasius, 232; of Locus- tide, 233 Tomognathus sublevis, only workers of, known, 87 note Tracks of ants illustrated, 251-257 Tuning-forks, experiments with, 222 Tunnels formed by ants, 25 Tyndall, Professor, experiment 448 TYP with sensitive flames, 225; as to sense organs in antenna, 228 Typhlopone, absence of eyes in, 11 LTRA-RED rays, ants not sen- sitive to, 206 Ultra-violet rays, sensitiveness of ants to, 201-220 Uropoda formicaria described, 429 ARIETIES produced in beetles frequenting nests of various ants, 77 Verrall, G. H., Esq., description of a new genus of Phorida, 26, 431 Vespa germanica, experiment with, as to communication, 415 -— vulgaris, experiment as to colour with, 316 Vibrations producing sensations of sound and colour, 225 Violet light, avoidance of, by ants, 189 Violets, colours of, 309: seeds of, carried into nests by Lasius, 26, 59 Viscidity of plants, a de'ence against insects, 55, 56 Vision among ants, 182; of the INDEX. WOR ocelli, 183: of compound eyes, 184; limits of, 199, 206, 219 ALKER, Mr., honey ant sent from Aastralia by, 48 Wasps, occasional fertility of workers among, 36; sense of hearing among, 221; experi- ments with, 311, 415; more clever than bees in finding their way, 313; their courage, 314; account of a tame one, 315; their colour sense, 316; their industry, 421 Water, ants’ visits prevented by, 52 Wesmael, M., describes Myrmeco- cystus, 47 Westwood, Mr., on the production of neuters, 22; on the sourd produced of Mutilla, 229 Wirgs of ants, atrophy of, among the workers, 12; pulled off after flight by the queen ants, 12, 19 Winter, aphis eggs tended by ants through the, 70 Workers among ants always wing- less, 12; varieties of form among, 19-22; occasional fer- tility of, 35 ; longevity of, 87, 88 (3) Plate 2. 1. Atta barbara ¥ major. 3. Pheidole megacephala ¥ major. oe; a “ minor. 4. “ minor. 5. Formica rufa. Plate 3. 4 3. Stenamma Westwoodii %. ce 1. 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