F5 CASE JC-NRLF THE FISH; WITH THE i'MINUTER ANIMALS OP THE OCEAN. PHILADELPHIA : PUBLISHED BY THE TRACT ASSOCIATION OF FRIENDS, AND TO BE HAD AT THEIR DEPOSITORY, NO.. 84 MULBERRY STREET, THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA PRESENTED BY PROF. CHARLES A. KOFOID AND MRS. PRUDENCE W.KOFOID Bvo\ THE FISH. I \W CHAPTER I. HUMBER OF FISHES THEIR STRUCTURE ADMIRA'BLE ADAPTATION OF THESE CREATURES TO THEIR CIR- CUMSTANCES. WE read in the first chapter of Genesis the command of the Great Creator, " Let the waters bring forth abundantly the moving creature that hath life." We also find in the next verse the result of His fiat who spake, and it was done, who commanded, and it stood fast. "And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind :" " and God saw that it was good." Fishes abound wherever flowing water is to be found, from the streamlet on the tops of our highest mountains, to the wide-spread oceans that encircle our globe. They seem to be quite as abundant in number and variety as animals are on land, or birds and insects in the air. After the whale, the shark is of the greatest dimensions, as it is from one thousand to four thousand pounds in weight, and is sometimes thirty feet long. The general structure of this extensive class 1 (1) 2 FORM OF A FISH. ft of animals, considered in reference to the ele- ment in which they live, exhibits much to excite our interest and admiration. This has been ad- mitted by some of our greatest philosophers, such as Galileo and Borelli, and with them the atten- tive reader of the brief statement now to be made, will, it is believed, fully concur. It is a curious fact, that mathematicians, after careful calculations, have found that the shape of a fish is that best adapted to enable it to pass easily through a fluid. What a beautiful testimony is this to the praise of Him who is " wonderful in counsel, and excellent in working !" A bird is formed for traversing the regions of the air ; but the feathered creature is far heavier than the thin element in which it raises itself, and through which it makes its way. The fish, on the con- trary, is nearly of the same specific gravity as the water in which it dwells ; and hence far simpler organs suffice to raise it in its native element, arid to guide and steady its movements. But this suspension of the fish in the water, with but little exertion on its own part, by a gentle agitation of its fins, greatly favours its progress. The bird has not only to sustain itself by beat- ing the air with its wings, but by the same strokes also to make its way. The fish, on the other hand, has only to be specially fitted for progres- sion through the element it inhabits. Its broad and powerful tail is the instrument which it uses for this purpose ; and we can see, as we watch the movements of the trout, that when it darte away, its fins are laid down close to its body. MOTION OF FISHES. 3 But the fins direct the fish, the pectoral fins es- pecially ; by raising or depressing the head they give direction to the whole body, under the force of the tail. The lateral fins, and particularly the pectoral fins, also sustain it in the right position in the water. As the intestines are below the centre, the belly would be turned up, but for the action of the lateral fins. This we see takes place in a dead fish. The incessant action of the muscles which move the tail and fins may well excite our admi- ration. If a fish move with his head down the stream, he must move more rapidly than the water, or else it gets under the lid of the gills, and chokes him. He lies, therefore, continually with his head to the stream. A trout may be observed lying for hours stationary, whilst the stream is running past him, and these creatures seem to remain so for days and nights. If, however, the general form of the fish is worthy of notice, it equally deserves attention, that while it has that compressed oval form, pofnted anteriorly and tapering behind, of which the salmon and mackerel may be cited as exam- ples, yet in slow-moving fishes, or such as creep on the bed of the sea, there is a greater or less departure from this form. To aid motion, the surface of the fish is tensely covered with an unwrinkled skin, clothed not with hair or feathers, but with smooth and glossy scales, lying as flat as possible, all regularly over- lapping each other, like slates or shingles on the roof of a house. Besides this, the surface is lu- 4 COLOUR OF FISHES. bricated by a fluid, which in some fishes, as the eel, where the skin, from the extreme minuteness of the scales, appears naked, is very abundant. Thus the progress of the animal is greatly aided, and it is also enabled to creep through small ori- fices, and to insinuate itself into the holes to which it retires for safety and concealment. Apistes marmoratus. Some of the perches are remarkable for their beauty : the red-finned perch of our own waters, and the gold and silver fish of China, so often seen here in vases, may be given as familiar ex- amples. Many others might be mentioned as arrayed in great beauty, such as the apistes, of which a representation has just been given. One, found in the Mediterranean, six feet in length, has a golden radiance ; and another, observed in the Nile, is covered with scales of a brilliant silver colour, like spangles lying close together. In other instances, there are various bright spots, bands, and crossings, and the blending of one bright hue with another. The beautiful silvering of our shad is well known to our readers, and is THE SOUND. 5 said to be occasioned by the presence of silver in the colouring matter of the scales. Some fishes have an internal organ, in refer- ence to which there have been many conjectures, but which most naturalists consider to act as a float, by the varying adjustment of which they are enabled to rise rapidly in the water, and yet so completely under control, as to permit them to descend with ease. This organ is commonly termed the swimming-bladder, or so^d. It is a long membranous sac, variable in form and ex- tent, running along the under surface of the spi- nal column, to which it is firmly attached. It is filled with air, usually what is called nitrogen gas, evidently secreted by its delicate lining. In many instances it has no opening; but in others, it communicates with the gullet by means of an orifice, which allows the escape of the air when the sac is compressed by the muscles provided for that purpose. Where the air-bag has no opening to act as a safety-valve for the escape of its gas, it is liable, under certain circumstances, to burst. Thus, for example, when the fish is suddenly drawn up from a considerable depth into the air, the sud- den expansion of the gas contained in the sound ruptures the membrane of that organ. This fre- quently happens to codfish, perch, and other fishes ; and the gas rushing into the general cav- ity of the body, not only distends it greatly, but even pushes the gullet and stomach up into the mouth. Such accidents, of course, would seldom occur to these fish in their native element, but 1* HEARING OF FISHES. are owing to their being suddenly removed from those deep waters to which their habits of life . consign them, and to the density of which their organs are adapted. The sounds of the cod and the ling are frequently employed in the mamufac- ture of isinglass ; but those of the sturgeon fur- nish the best .materials, and are in the greatest request. The tenants of an element more dense than our atmos^lere, less capable of conveying sound or transmitting rays of light, often turbid, and, moreover, but little adapted for the diffusion of odorous particles, require, of course, senses less refined and delicate than creatures inhabiting a rarer element. Unlike animals, which express their instinctive feelings by various sounds, fishes, \^th few exceptions/ are mute. Many, besides, live at a depth to which, while the surface is tempest-tossfed, the roaring of the;billows cannot extend. Accordingly, the organ* of hearing lies deep beneath the skin, and is very simple in its structure. The ear of a fish consists only of a labyrinth, composed of three semicircular canals, communicating with'a chamber, and placed in a wide cavity on each side of the head, and sur- rounded by a glassy fluid. To each of these canals, the auditory nerve sends a filament, which spreads in the form of a beautiful net-work over the inner lining of the chamber. The engraving on the opposite page shows this structure. The chamber and the canals are filled with a fluid, and the former contains certain calcareous bodies, extremely hard, called ear-stones. They HEARING OF FISHES. 7 are generally three in number : their form differs greatly in the various species ; but in every indi- vidual of the same species they are the same. They are generally suspended in the chamber by means of delicate filaments. In -the shark, and some other fishes, they have neither the enamel gloss nor the hardness apparent in other cases ; they resemble moistened starch, and consist of chalk, with a portion of gelatine. Ear of a Fish, a, a, a, semicircular canals; b, 6, the chamber with which they communicate ; c, the auditory nerve sending forth its filaments. As a proof that fishes have in some degree the power of hearing, it is stated that there is a sin- gular mode of taking trout practised in some of the rivers in South Wales. ' The sides of the rivers are here and there very rocky, and where 8 HEARING OP FISHES. there is a flat shelving rock, trout generally haunt under it. On the rock being struck forcibly with a large sledge-hammer, the trout rise to the sur- face of the water, appearing as if they were stunned, and are then taken. With so simple an organ of hearing, it is sup- posed that fishes cannot distinguish the differ- ences of tone, and that all sounds are to them nearly the same. It appears that these sounds vary in intensity, according to the more or less violent vibrations of the fluid contained in the labyrinth, and the agitation of the ear-stones. But the vibration of this fluid must depend on the vibration of the walls of the cavity in which the labyrinth is lodged ; and these walls must be affected by the vibration of the waters in contact with their external surface. That noise produces in fishes a powerful sensation, may be admitted ; but it is questionable if their ear appreciate dif- ferences of tone, like that of birds and quadrupeds. Those fishes whose lives are spent in the shal- low waters of rivers and small streams, we have reason to believe, are more affected by sounds than those which inhabit the depths of the ocean, and are not exposed to the same class of dangers as the former. Every angler knows that he must approach the margin of a stream cautiously and quietly, if he wishes to succeed in trout-fishing ; for were the fish ever so plentiful, a noisy person will stand little chance of catching any, even where the experienced fisher will fill his basket. Trout, pickerel, perch, and other fish have been domesticated in artificial ponds, and have soon VOICE AND SMELL OF FISHES. 9 learned to know the voice of their feeder, and greedily answer to his call to be fed. Many in- stances of this kind are on record, clearly proving the organs of hearing in some, at least of the fresh-water fish, to be sufficiently acute to enable them to distinguish simple sounds. In most of the instances noticed, the fish were called by whistling ; in one, by drumming on a wooden box containing their food. Though fishes are destitute of what we can call voice, there are still some of them capable of producing distinct sounds, no doubt answering some wise purpose in the economy of the animal. The drumfish of our own coast owes its name to a loud drumming sound it emits, and which is said to be audible to a great distance. Some of the smaller fish of our rivers are also known to denote their pain, when caught by the angler, by the utterance of faint cries. It appears to be rather by sight than smell that fishes seek for and pursue their prey. The latter power is feebler than the similar gift to other creatures. Thus fishes seize artificial flies, and imitations of other fishes, as well as of frogs and mice, which, were they guided by the smell, they would not do. In asserting, however, that this is not their principal means of discovering food, it is not pretended that fishes do not use their smell in the selection of food ; some, it is reason- able to conclude, do so more than others. Trout may be observed motionless in a river, with their heads directed against the stream, and evidently watching, not smelling, for their food ; and they 10 SMELL AND SIGHT OF FISHES. may be seen not only darting at flies which settle on the surface, or*at small fishes wandering near, but at an artificial fly which the angler has thrown within their reach. We know, too, how passing clouds, casting a fleeting shadow on the water, alarm them; how they retire if they see the angler clearly ; how the weak avoid the strong, and the strong pursue the weak : all this involv- ing sight, but not smell. Unlike what we find in higher orders of creatures, the organs of smell do not communicate with the back of the mouth : they consist of two cavities near the front of the mouth, lined with a fine membrane, variously folded, in order to increase the extent of surface, which is supplied by filaments of the olfactory nerves. The nostrils are simple orifices for the admission of the water, which, having no outlet to pass through immediately after entering, re- mains longer than the air does when passing through the nostrils of quadrupeds. Hence the succession of impressions on the olfactory organs of fishes is less rapid. The sense of taste in fishes is evidently fee- ble. The tongue is but imperfectly developed : it is covered with the same skin that lines the rest of the mouth, and is often furnished with teeth. Fishes seize their food and swallow it at once ; they do not masticate it, and have no sali- vary glands, so important to other creatures. The eye is the most important organ of sense with which fishes are endowed. It is expressly adapted to bring the rays of light to a focus on the retina in a denser medium than the air. As SIGHT OF FISHES. 11 among other animals, there is a very great differ- ence in the size of the pupil, andlof the eye itself. In one instance, that of the anableps, there is a double pupil in each eye. Fish'es which reside in the depths of the ocean, where the light of day scarcely reaches them, or where there is at most an obscure twilight, have the eyes large, like those of nocturnal quadrupeds or birds. On the contrary, such as live in mud, and burrow in the oozy slime of rivers,*or low shores, have the eyes small, and often rudimental. In the myxines there are no traces of eyes. There is a small fish sometimes caught in the Great Cave in Ken- tucky, resembling our catfish, which has no eyes, nor even the rudiments of them. We give the following as an interesting in- stance of the powers of sight in fishes. Being, on one occasion, in a large steamer at the mouth of Delaware bay, at night-fall, our captain dropped anchor close in to the eastern shore, within Cape May. The evening looked very stormy, and the night proved to be so, giving both captain and men much uneasiness lest we should, before morning, part both our cables and be driven out to'sea. But though the night was stormy, it was one of much interest to us; for the heavy waves, as they rolled in from the ocean upon us, exhib- ited all the beauties of that remarkable phenome- non, phosphorescence of the sea. Far as the eye could reach, the combing of each wave was tipped with the liquid light, the incessant flashing of which was indescribably brilliant. Our attention was particularly struck with the motion of the 12 SIGHT OF FISHES. fish, which appeared in considerable numbers round our vessel, varying in size, apparently, from a foot to six or eight feet in length. The phosphorescence of the water was so great as to illuminate each fislvand enable us to trace them, even when they descended to considerable depths. The larger fishes were evidently preying on the smaller; and the varied evolutions by which these endeavoured to elude their pursuit were very interesting. Now they*would dart off at a sudden angle, rise to the surface, and again pass- ing under the keel of the steamer, rise on the other side. At one time they would be at the bow, at another at the stern ; but go where they would, their motions in the water induced suffi- cient light to enable both ourselves and their more dreaded enemies to trace their movements. The respiratory organs of fishes exhibit variety of structure; but our space will confine our atten- tion to the ordinary groups. In these they con- sist of the gills, which have a lid capable of being Head of the Herring, a, the gill-lid; I, the gill-flap. EEfePIRATION OF FISHES. 13 opened at pleasure, and a gill-flap, which assists also in covering the gills. As it is moveable, like a fin, independently of the gill-lid, it may assist the mouth in throwing a current of water over the gills, or it may effect this when the mouth is occupied with food. On raising the part just described, we see be- neath it the gills, of a beautiful red colour, com- posed of arches, varying in different species, and fringed with a series of fibrils, set like the plume- lets composing the vane of a feather. When these are minutely examined, they appear covered with a velvet-like membrane, over which myriads of wonderfully minute blood-vessels are spread, like a delicate net-work. There are commonly four of these fringed arches : they are moveable, and allow the currents of water, driven down by the action of the mouth, to flow freely through them, so as to lave every fibril. The concave margin of each arch is always more or less stud- Head of the Herring, with the gill-cover entirely removed, a, the gill-fringes, on the posterior margin of the arch; ft, the anterior slender spines directed forwards ; c, position of the heart. 2 14 CIRCULATION OF BLOOD IN FISHES. ded with tooth-like projections, and these in the herring, and some others, are lengthened into slender spines. Their use appears to be, to pre- vent, food taken into the mouth from being forced out through the gills with the streams of water sent through them. The heart of the fish is designed to supply the gills with blood. It consists of an auricle and a ventricle, -and also of a capacious reservoir to receive the blood returned from the body, prior to its being admitted into the heart. The en- graving shows the course of the circulation. The blood being received into the auricle, is carried into the ventricle through an opening guarded by valves, and thence it is sent through the branchial artery to the gills. Here the ar- tery divides into as many branches as there are arches; and each branch runs in a groove along the convexity of each arch, sending off a Heart of a Fish. , the still finer branch to every auricle; 6. the ventricle; /^i -i >i /* C) the branchial artery. fibril, this again ramifying into a net of most delicate tubes. It is in the fine blood-vessels of the fringe of the gills that the blood is acted upon by the oxygen of the water, and from the gills it is car- ried to the general system. Fishes are endowed with much less vitality than warm-blooded ani- mals, respiring simply through the medium of CIRCULATION OF BLOOD IN FISHES. 15 water ; in other words, only availing themselves of the small quantity of oxygen which is contained in the air mixed with water. The number of aquatic respirations in fishes is between twenty and thirty in a minute ; and the surface of the gills over which the blood is distributed, that the water may act upon it, is surprisingly great. It has been calculated that the gills of a large skate present a surface equal to 2,250 square inches, or about the whole exter- nal surface of the human body. One creature, the Perca scandens, has a very remarkable struc- ture adapted to maintain respiration, and, conse- quently, to support life for a considerable time when out of the water. It is said to travel occa- sionally on land to some distance from the coast. The bones of the cavity in which the food is re- ceived in its passage from the mouth to the gul- let, are so constructed as to have a capacity for retaining a sufficient quantity of water not only to keep the gills moist, but also to enable them to act properly, while not a particle of water is suffered to escape, the lids being accurately closed. Dr. Hancock, in the Zoological Journal, gives an account of a species of fish, probably allied to the perch above described, which in very dry seasons, when the pools in which they commonly reside lose their water, remove by land in search of others, where the water is not evaporated. These fish grow to about a foot in length, and travel in large companies ; using the pectoral fin as a kind of foot, they push themselves forwards 16 FOOD OF FISHES. by means of their tail, moving nearly as fast as a man will leisurely walk. A friend of Dr. Han- cock, resident in Essequibo, once fell in with a drove of these animals, which were so numerous that the Indians in his company filled several baskets with them. Most fishes are carnivorous, preying on the smaller of their own class, and on worms, insects, and various other creatures ; but some feed in part, and some few, perhaps, exclusively, on ve- getable productions. Well may we say with the Psalmist, in the review of the circumstances now stated, in reference to the structure of these crea- tures, and the means provided for their support : " O Lord, how manifold are thy works ! in wis- dom hast thou made them all : the earth is full of thy riches. So is this great and wide sea, wherein are things creeping innumerable, both small and great beasts. These wait all upon thee, that thou mayest give them their meat in due season. That thou givest them they gather : thou openest thine hand, they are filled with good." (Psa. civ. 2428.) In thus referring to the provision made for in- ferior creatures, it is of great importance that the mind should dwell also on the provision made for ourselves. The gifts of God, bestowed during every moment of our lives, demand our sincere and fervent gratitude, while there are blessings bestowed on us as immortal beings, for which we should be still more thankful. Our highest praise is due for the manifestation of his mercy to us as sinners, through " the Lamb that was THE GREAT SALVATION. 17 slain." The gospel goes forth, offering the bless- ings of pardon, renovation, and hope, to be en- joyed now, and all the glory and happiness of heaven to be participated hereafter, to all who believe its testimony, and " repose the whole affiance of their souls" on the crucified Redeemer. " I am," he says, " the light of the world : he that followeth me shall not walk in darkness, but shall have the light of life." (John viii. 12.) His voice is heard saying, " Come unto me," and " him that cometh to me I will in no wise cast out." (Matt. xi. 28 ; John vi. 37.) " Therefore," says the great apostle of the Gentiles, " we ought to give the more earnest heed to the things which we have heard, lest at any time we should let them slip. For if the word spoken by angels was stedfast, and every transgression and disobe- dience received a just recompense of reward ; how shall we escape, if we neglect so great sal- vation r (Heb. ii. 13.) CHAPTER II. SINGULAR FISH THE SAW-FISH THE SWORD-FISH THE SUCKER-FISH THE FLYING-FISH THE TORPEDO THE ELECTRICAL EEL. THE space which remains to be occupied, will allow only of a reference to a few remarkable tenants of the deep; but it is hoped that the con- templation of these will lead to further inquiry as to creatures exhibiting in various ways the perfections of the adorable Creator. One fish, about six or eight inches long, fre- quents the waters of the East Indies. When it observes a fly on the plants that grow in the shal- low water, it swims to the distance of five or six feet, and then, with surprising dexterity, ejects from its tubular mouth a single drop of water, striking the fly into the sea, where it soon be- comes a prey. Among the monsters of the deep, whose vora- city and weapons of attack render them terrible to their prey, one of the most remarkable is the saw-fish, which inhabits the northern and tempe- rate latitudes of the ocean. Nearly allied to the sharks, it has all their ferocity, and more than their power, being armed with a weapon of de- struction which makes it victorious even over the grampus and the whale. This is a kind of saw, of a flattened form, projecting from the snout, armed along the edges with tremendous teeth, (18) THE SWORD-FISH. 19 A saw recently examined, taken from an adult individual, measures five feet in length, and is nearly one foot broad at the base, whence it tapers to the apex, which is rounded, and mea- sures five inches across. It is about one-third the length of the whole body. Head of the Saw-fish. Another is remarkable from the upper jaw being lengthened into a flat, sharp beak, which resembles a sword, but is far more strong and solid. With this weapon the sword-fish attacks whales, and even ships. When the Leopard, from Guinea, was cleaned in 1725, the beak of one of these creatures was found in the bottom of the vessel : it had passed through the copper sheathing and a three-inch plank, and even four inches beyond that into the solid timber. The fish had followed the ship, and struck it while under sail, and the beak must have broken off in the animal's strug- gles to disengage it. At the present time there is in the British Museum part of the hull of an East-Indiaman, with the sword of a fish driven completely through it, almost to its base. Sir Joseph Banks was informed by the captain of the vessel, that the fish killed itself by its prodigious exertions in the blow. 20 THE SUCKER-FISH. The sucker-fish is also a remarkable little creature. It inhabits the tropical seas, and de- rives its name from the top of the head being provided with a large oval disc, by means of which it adheres to other bodies, and that with astonishing tenacity. This apparatus is surround- ed by a broad > loose, moveable rim, within which are two rows of cartilaginous plates, having each a free edge, which is finely toothed, like a saw. These plates can be raised up, or depressed, so as to bring them flat, at the will of the fish, there being peculiar muscles on the skull adapted to that purpose. These two rims are separated merely by a thin partition, and are thus divided, most probably, that, being shorter, each may gain an increased degree of firmness, so as to exert a greater muscular force. Head of the Sucker-fish. This singular provision acts like the leather sucker which the schoolboy presses on a stone, removing the air from beneath, so that the pres- THE SUCKER-FISH. 21 sure of the atmosphere on the upper surface may cause his sucker to adhere to the stone. The rim of the fish being closely applied to any sur- face, the plates lying flat, are forcibly raised up, and the interstices, therefore, become so many spaces free from air, while the saw-like edges of the plates, the raising of them having once taken place, retains sufficient hold of the substance in contact to continue in that position, aided by the pressure of the surrounding water, without any further muscular exertion. Nothing can be more simple than this apparatus, and nothing more complete in its operation. It is a compensation for the feeble locomotive power of the fishes to which it is granted ; for by this means they avail themselves of the exertions of others to pass through the water. Even to the sides of the shark, that huge tyrant of the deep, the sucker- fish attaches itself without fear, led by that in- stinct with which it has been endowed by the great Creator, to provide for its wants and safety. In a cabinet in Philadelphia is preserved a pair of these singular fishes ; they are about five inches in length, and were taken from the body of a shark. They were found firmly adhering to his sides, just below his mouth, in such a situation that they might readily catch the refuse food that escaped from the jaws of their greedy bearer, while in a place of entire security for themselves. The flying-fish, represented on the title-page, will also repay our attention. In birds, flight is accomplished by feathered wings ; in the insect tribes by net-work fans ; in the bat by membra- 22 THE FLYING -FISH THE BONITO. nous expansions, supported by the bones of the limbs ; and in the flying-fish by a fan-like exten- sion of the pectoral fins. This creature, of which there are two or three species known, is a native of the seas of the hot- ter regions. It abounds between the tropics, nor is it uncommon in the Mediterranean, or off the coast of Spain. One of the species frequents the bays of the coast of the United States. It often happens that, in clear water, shoals of these fishes may be seen quietly pursuing their course, in search of food, when suddenly the dolphin, or the bonito, cleaving the water like an arrow, advances upon them. Now begins the struggle ; this for his victim, those for life; away skims the shoal of flying-fish, and forward presses the untiring depredator, gaining rapidly on his booty, whose long spring-like fins seem almost an impediment. The enemy is already upon their ranks, the fate of the hindmost seems inevitable, when at once rising like birds from the surface of the deep, upborne on transparent quivering wings, the glit- The Bonito. THE DOLPHIN. 23 tering shoal dazzles the eye as it skims along, leaving the pursuer in the distance. Short, however, is the flight of the flying-fish. Its delicate fans are soon dried in the sun, and our air is suffocating. In a few seconds, the shoal, which reflected like silver the beams of the sun, descend into their native element, and again are farced to flight; and this is repeated either till, exhausted by their efforts, they fall victims to their conqueror, or till they have baf- fled his hound-like perseverance. But the poor flying-fish do not always find safety in the air; and their short flight often makes them the prey of another enemy. While the dolphin or the bonito harasses it in the water, hunting it as the wolf hunts down the deer, the frigate-bird and the albatross are ready to pounce upon it in the air. Sailing in the sky, and always on the watch, The Dolphin. 24 THE TORPEDO. they mark the motions of the finny tribes below, and sweep down with unerring aim upon their prey. The flying-fish is an easy mark. It would appear, however, that it is not only when pressed by their enemies, that these curious fishes try the upper air; they often, as if in the exuberance of enjoyment, take short and reiterated flights, just dipping on the water, and rising again, when no foe can be observed. The electrical power of fishes is another cu- rious fact; some of them being able instantane- ously to produce a convulsive contraction of the muscles of individuals : in other words, a shock. One of these is the torpedo, which is closely allied to the ray, or skate. The disc of the body is. nearly circular ; the tail is short and fleshy. The electrical organs consist of a number of up- right hollow columns, situated on each side of the cranium, and extending backwards as far as the gill-openings. The cavity of each column is divided by transverse partitions into a number of cells, containing a jelly-like fluid. These partitions, in a column of one inch, amount to one hundred and fifty. They consist of a very fine membrane. The whole apparatus is covered with one which is very thin a mem- brane composed of longitudinal fibres, united to the skin or surrounding parts of the body. These electrical organs are supplied by a large number of nerves, on which their peculiar power entirely depends. They are doubtless intended to sub- serve the continuance of life in a two-fold man- ner. The power they exert affords protection THE ELECTRICAL EEL. 25 by enabling the torpedo to benumb its foes, and they assist in procuring food, by stunning or kill- ing the smaller animals on which it feeds. Another of these creatures is the Gymnotus electricus, or electrical eel. When full-grown it measures between five and six feet in length. Its colour varies with age, and the nature of the water in which it dwells. Generally, it is of an olive-green, with the under part of the head of a yellow tint mingled with red ; and a double row of small excretory openings in the skin from the head to the tail are thus coloured: these openings appear to belong to mucous glands, which secrete the slimy fluid with which the skin is lubricated. The mouth is wide, and the interior, as far as the gullet, is furnished with little teeth disposed in rows, and very closely set ; the tongue is fleshy, and covered with papillae. It may be asked, What is the structure of the apparatus which gives to this eel its terrible powers, and renders it capable of discharging an electric shock of such violence as to throw down horse and man ? The organ which produces these singular effects occupies the under parts of the tail, or terminal portion of the body. It consists of four longitu- dinal masses ; two large above, two small below, each being composed of a vast number of mem- branous laminae, or thin plates, closely set toge- ther, and nearly horizontal. These plates have their external margin affixed to the skin, and they rise to a level with the vertebral column ; they are besides united to each other by an infi- nite number of transverse small vertical laminae, 26 THE ELECTRICAL EEL. and thus are formed a multitude of transverse cells, or minute prismatic canals, filled with jelly- like matter, and abundantly supplied with nerves. a a, the upper and larger pair of electric organs?, b b, the lower pair, c c, two muscles dividing the upper from the lower pair of electric organs, d d d d, four external lateral muscles, e, a single muscle inserted into the fin,/, g g, eight dorsal muscles, imbedded in fat and cellular tissue, and having a concentrically laminated structure, h, the spinal column, i, the swimming-bladder, which is of an elongated form and of great length, measuring from two to nearly three feet. "I never remember," says Humboldt, "to have THE ELECTRICAL EEL. 27 experienced a more terrible blow from the dis- charge of a Leyden jar of great size, than one which I received on putting my two feet on a gymnotus which was dragged out of the water. During the rest of the day, I felt great pain in the knees and in almost every joint of the body." It is scarcely necessary to say, that in the pools*, lakes, or mexes, tenanted by this formidable fish, it reigns supreme ; what, indeed, can withstand its assaults? It comes not upon its foe with teeth, nor the common weapons of its race, for then force might be opposed to force; but it deals destruction by the agency of means against which strength and courage are of little avail. The sketch on the opposite page represents a section of the terminal portion of its body, con- taining the electrical apparatus in its natural situation and may serve to convey an idea of the arrangement of its plates, and the relative mag- nitude of the upper and lower double series. On the nerves with which these creatures are furnished depends their electric power ; but how, or in what manner, the accumulation of electric fluid takes place ; the means which the animal has of discharging it, or not, at pleasure, or in what direction it pleases ; and the theory of its production these points are all enveloped in mystery. We are presented with nerves, and a large laminated apparatus; and we find that these nerves and this apparatus of plates constitute, in some mysterious manner, an electro-galvanic bat- tery, governed as to its use by volition ; but we know no more. How soon are we stopped by 28 THE WONDERS OF CREATION. impassable barriers in the progress of our inves- tigations among the wonders with which the great field of creation teems ! How soon do we dis- cover the limitation of our minds, and their inad- equacy to grasp a part, a small part, of the ways and workings of the Almighty ! MINUTE ANIMALS OF THE OCEAN. THE innumerable tribes of insects which swarm in every part of the world, delighting us by the brilliancy of their colouring, or tormenting us with their attacks upon our persons or our property, although their armies sometimes render whole countries uninhabitable, destroying every blade of grass in their career ; even these seemingly interminable hosts must yield the palm in number, beauty, everything except destructiveness, to the sky-tinted denizens of the ocean. Every leaf of sea-weed, every fragment of floating timber, teems with life, in some of its most interesting forms, and the blue expanse of waves is everywhere studded with animated germs, which sail along its surface, or lie hidden in its bosom. The seaman, as the vessel hurries along, catches occasional glimpses of misty specks floating be- neath him, which, to his careless eye, appear like the spawn of fishes, or the slime washed from their bodies; yet in these unpromising and neglected atoms, closer examination discovers beings whose delicacy of structure defies the pencil, and whose tints are rivalled only by those of a summer's evening. There is a striking contrast between the gran- 3* () 30 MINUTE ANIMALS deur and the immensity of power displayed by the angry waves, and the delicate and fragile forms which crowd their surface. The crest of a billow, which causes the tough fir-ribbed vessel to tremble beneath it, passes harmlessly over myriads of beings, which, when removed from their native element, dissolve under the fervour of the sun, or break in pieces by their own weight. Yet, unobtrusive as are these lower links in the scale of nature, they are often individually dressed in great beauty, and collectively, they produce some of the most sublime phenomena, building up islands in the midst of the deep, or alarming the mariners with the appearance of unreal shoals. Those who have sought relief from the summer heats at Long Branch, or Cape May, have proba- bly noticed in their ramblings along the beach, certain gelatinous transparent masses, deposited by the receding tide upon the sands. They re- semble very large plano-convex lenses, and are devoid of colour, except in a few minute points, which appear like grains of yellow sand, or the eggs of some shell-fish imbedded in their sub- stance. This has led many to consider them as the spawn of some marine animal. If one of these jellies be placed in a tub of brine, immediately after it reaches the shore, the observer will be surprised to find it possessed of animation. The upper, or convex part, will ex- pand like the top of an umbrella, and from its under surface several fringed and leaf-like mem- branes will be developed. The remains of numer- ous threads, or tendrils, will float out from the OP THE OCEAN. 31 margin of the umbrella, following the motions of the animal as it swims around the tub. These threads are often several feet in length before they are broken by the sand ; they are probably employed both to entice and secure the prey, and they often produce a sharp, stinging sensation, when applied to the skin. It is from the appear- ance and offensive power of these last organs, that seamen have given the animal the title of the sea- nettle, and naturalists the generic name, medusa. This rude description of the medusa is offered as a familiar example of the class of animated be- ings which are the subject of the following re- marks. They are all alike gelatinous ^nd trans- parent, and many of them melt and flow away when exposed in the open air to the direct rays of the sun. Of all the tribes of molluscoe which are scat- tered over every part of the ocean, the most splendid, and the best known, is the Portuguese man-of-war. This is an oblong animated sack of air, elongated at one extremity into a conical neck, and surmounted by a membranous expansion, running nearly the whole length of the body, and rising above into a semicircular sail, which can be expanded or contracted to a considerable extent, at the pleasure of the animal. From beneath the body are suspended from ten to fifty, or more, Jittle tubes, from half an inch to an inch in length, open at their lower extremity, and formed like the flower of the blue-bottle. These appear to be so many independent stomachs, in which the food is received and digested. From the centre of this 82 MINUTE ANIMALS group of stomachs hangs a little cord, never ex- ceeding the fourth of an inch in thickness, and often forty times as long as the body. The size of the Portuguese man-of-war varies from half an inch to six inches in length. When it is in motion, the sail is accommodated to the force of the breeze, and the elongated neck is curved upward, giving to the animal a form strongly resembling the little glass swans which we sometimes see swimming in goblets. It is not the form, however, that constitutes the chief beauty of this little navigator. The lower part of the body and the neck are devoid of all colour, except a faint irridescence in reflected lights, and they are so perfectly transparent that the finest print is not obscured when viewed through them. The back becomes gradually tinged, as we ascend, with a fine and most delicate blue ; the base of the sail resembles the purest sky in depth and beauty of tint ; the summit is of a splendid red, and the central part is shaded by the gradual intermixture of these colours through all the in- termediate grades of purple. Drawn as it were upon a ground-work of mist, the tints have an aerial softness far beyond the reach of art. The group of stomachs is less transparent, and although the hue is the same as that of the back, they are, on this account, less elegant. By their weight and form, they fill the double office of a keel and ballast, while the cord-like appendage, which floats out for yards behind, is called, by seamen, the cable. The mode in which the animal secures his prey, OF THE OCEAN. 33 has been the subject of much speculation, for the fish and crabs that are frequently found within the little tubes, are often large enough to tear them in pieces, could they retain their natural vigour during the contest. Deceived by the extreme pain whictris felt when the cable is brought into contact with the back of the hand, naturalists have concluded that this organ secretes a poison- ous or acrid fluid, by which it benumbs any un- fortunate fish, or other animal, that ventures within its toils, allured by the hope of making a meal upon what, in its ignorance, it has mistaken for a worm. The secret will be better explained by a more careful examination of the organ itself. The cord is composed of a narrow layer of con- tractile fibres, scarcely visible when relaxed, on account of its transparency. If the animal be large, this layer of fibres will sometimes extend itself to the length of four or five yards. A spiral line of blue bead-like bodies, less than the head of a pin, revolves around the cable from end to end, and under the microscope these beads appear covered with minute prickles, so hard and sharp, that they will readily enter the substance of wood, adhering with such pertinacity that the cord can rarely be detached without breaking. It is to these prickles that the man-of-war owes its power of destroying animals much its superior in strength and activity. When anything becomes fastened upon the cord, the contractile fibres are called into action, and rapidly shrink from many feet in length to less than the same number of inches, bringing the prey within reach of the 34 MINUTE ANIMALS little tubes, by one of which it is immediately swallowed. This weapon, so insignificant in appearance, is yet sufficiently formidable even to man ; and if a person becomes entangled with the cable of a large man-of-war, the pain which it inflicts is almost insupportable, and sometimes does not en- tirely cease for twenty-four hours. We might now proceed to describe many analo- gous animals scarcely inferior in interest, but it is time to notice some of another tribe, residing beneath the surface, and therefore less generally known. The grandest of these is the beroe. In size and form it resembles a purse, the mouth or ori- fice answering to one of the modern metallic clasps. It is perfectly transparent, and in order to distinguish its filmy outlines, it is necessary to place it in a tumbler of brine, held between the observer and the light. In certain directions, the whole body appears faintly irridescent, but there are several longitudinal narrow lines, which re- flect the full rich tints of the rainbow in the most vivid manner, for ever varying and mingling the hues, even while the animal remains at rest. Under the microscope, these lines display a suc- cession of innumerable coloured scales, or minute fins, which are kept unceasingly in motion, thus producing the play of colours by continually changing the angle of reflection. The movements of the beroe are generally re- trograde, and are not aided by the coloured scales, but depend upon the alternate contraction and OF THE OCEAN. 35 dilatation of the mouth. The lips are never per- fectly closed; arid the little fish and shrimps which play around them are continually entering and leaving them at pleasure. The animal is dependent for its food upon such semi-animated substances as it draws within its grasp by moving slowly backwards in the water, and it retains them in consequence of their own feebleness and inability to escape the weakest of snares. Another tribe of sea-purses (salpa), though much smaller than the beroe, are more complex in structure, and possess a higher interest, in con- sequence of the singular habits of some of the species. They are double sacks, resembling the beroe in general form, but destitute of irrides- cence. The outer sack or mantle rarely exceeds an inch in length, and is commonly about half as wide. The inner sack is much smaller, and the interval between these forms a cavity for the water which they breathe, and for some of the viscera. The alimentary canal is as fine as horse- hair, with a slight enlargement at one spot, which has been called a stomach. This enlargement resembles, both in size and colour, a grain of sand. From the base of the animal arise two longer, and four or five shorter, conical spines of jelly, curved into hooks at_the points, by means of which numerous individuals attach themselves together in double rows, like the leaflets of a pinnated leaf. To the gregarious habits of this little mollusk, we owe a very singular and striking phenomenon. 36 MINUTE ANIMALS OF THE OCEAN. The animSjp-.'are occasionally found associated to- gether in si\ch countless myriads that the sea is literally filled with them, sometimes over three or four square miles of surface, and to 'the depth of several fathonfs. The yellow spots which have been described being the only coloured portions of their body, give to the whole tract the appearv ance of a shoal or sand-bank at somp distance be- low the surface. The deception* is heightened by the greater smoothness of the water a^jjpese places, particularly in calm weather; for sQJff^cly .are the animals crowded together, that tnWvater is rendered, in a manner, less fluid ; the smaller billows break around the margin abd are lost, while the heavy waves of the ocean are somewhat opposed in their progress, and take on, in a slight degree, the usual appearance of the ground-swell. There can be but little doubt that many of the numerous shoals laid down in the charts, but which have never been seen by any but the sup- posed discoverers, have been immense banks of these gregarious molluscse. One writer mentions that in sailing through a tract of this description, in which the progress of the ship was very sensi- bly retarded, he dipt up, with the ship's bucket, a greater bulk of the animals than of the water in which they were suspended. How wonderful are the effects produced by the minute links of creation ! FINIS.