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the pectoral fins resemble short arms, and are palmated at their tips.* M. Renau, in his History of Fishes, affirms that he knew an individual of this species; and the expression is not so incorrect; as he saw it for three days living out of water, walking about the house in the manner of a dog. The circumstance of the lophius walking out of water has some interest, from showing that relations may subsist between organs apparently the least connected with each other. In this genus, the operculum, which covers the gills, does not open widely, as in most fishes, to let the respired water pass off freely behind; the water is discharged by a small aperture, capable, in Mr Owen's opinion, of being closed by a sphincter muscle; when, the cavities where the branchia lie being large, a considerable quantity of water may be confined within them. Thus, not only are the fins of the fish converted into feet, but the gill-covers into pouches, capable of containing water sufficient for respiration when the sea has retired. Then the lophius, lying in the mud or shallow pools, and watching its prey, angles for it in a very curious manner. Pliny relates that it will bury its body, and leaving the glittering filaments which float from its head exposed to view, like worms, will entice the smaller fishes.
But, besides the "harlequin angler," other fishes perambulate the dry land; and even ascend trees (without being carried there by floods). Thus a particular fish (perca scandens) can clamber a tree by means of the spines of its gill-covers, and spinous rays of its fins; whence Dr Shaw called it the climbing-fish.+
All animals protected by feathers, or shells, or scales, are endowed with an exquisite sense of touch in the mouth, or in appendages belonging to it. Fishes have hanging from their lips processes called cirri, which are equivalent to the feelers or tentacula of insects and crustacea. The fishing lines of the lophius are examples of these processes.
It is surprising how varied are the means by which fishes obtain their food. The bandoulière à bec (chelmon rostratus, of
* These fins have two bones like the radius and ulna; but Cuvier says that they are more strictly bones of the carpus.
The spines of the Echinus, or Sea Urchin, are moveable; they assist
in progression. They are directed against an advancing enemy! Although these spines may be effectual for their purposes, they are to be regarded as the lowest, or least perfect substitutes for extremities.
the genus Chaetodon rostratus), squirts water at flies as they pass, brings them down, and then feeds upon them. The sciana jaculatrix, according to Pallas, possesses a similar skill; and the sparus insidiator surprises aquatic insects by the sudden projection of its snout. As to the elongated rays of the dorsal and anal fins in the cordonnier of Martinique (zeus ciliaris, le blepharis, Cuv.), some naturalists affirm that they are employed to coil round the stems of plants, in order to sustain the fish. The several offices attributed to these processes in fishes, almost implies that they must possess sensibility, if not muscular
Some years ago I discovered, by anatomical investigation and experiment, that, in man, the sensibility of the head and its various appendages, as well as the power of closing the jaws and masticating, depended upon one nerve alone of the ten which arise from the brain, and are distributed within and around the head, viz., the Fifth.* By the aid of comparative anatomy, I found also that a corresponding nerve served similar purposes in the lower animals. In those covered with feathers or scales, or protected by shell, this nerve becomes almost the sole organ of sensation. It gives sensibility to the cirri of fishes, and to the palpi of the crustacea and the antennæ of insects. It is the same nerve which supplies the tongue, and is the organ of its exquisite sensibility to touch, as well as of taste. In some animals, especially reptiles, the tongue, by its length and mobility, becomes a substitute for these external appendages; and in others, besides serving for touch and for taste, it is an organ of prehension. With it the ox gathers in the herbage; and in the giraffe it is curious to observe that, as the whole frame of the animal is calculated to elevate the head to a great height, so the tongue is capable of projecting beyond the mouth to an extraordinary extent, and of wrapping round and pulling down the extreme branches of trees.
[What could have tempted Buffon to express his pity for the woodpecker, as abject and degraded? and why should this bird be described as leading an insipid life, because continually employed in boring and hammering the old stump of a tree? A late naturalist describes the woodpecker as enjoying the sweet
* See the Account of the Author's Discoveries in the Nervous System, at the commencement of the volume.-(S.)
hours of the morning, on the highest branch of the tallest tree, fluttering and playing with his mate and companions. No doubt his diligence, perseverance, and energy in plying his beak are very extraordinary. But, besides the wedge-like strength of the beak, and the power of the neck to strike with it, there is something remarkable in its sensibility. That nerve, the Fifth pair, on which we have shown that all the sensibility of the head depends, transmits along the inside of the mandibles a large branch, which, as it approaches the extremity, perforates the bone by innumerable small canals, so as to reach the horny covering. The beak, thus possessed of sensibility, can be used to grope in the crevices of the wood, and under the bark. The woodpecker is enabled by this means, to direct the tongue, which moves with extraordinary celerity, and with a point like a barbed arrow. We have represented the dissection of the head of this bird more accurately in its anatomy than is to be found in books. We offer it because it exhibits a very curious piece of mechanism, adjusted to the tongue, to enable the animal to thrust it out far, and with unusual rapidity. a, is the barbed tongue; b, two slender elastic ligamentous cartilages, of very peculiar structure and use; on one extremity they are attached to the bone which supports the upper mandible; from this we trace them over the skull down upon the sides of the neck; and, with a large sweep, turning under the lower mandible, and so continued into the tongue, and not terminating until they reach the horny point, c c c, a long muscle which follows these ligamentous cartilages upon their concave side,
arising from the bone of the lower mandible, and so sweeping round with the cartilages and over the skull, to have another fixed point at the upper mandible: these protrude the tongue. Two muscles are seen to arise from the sides of the larynx, which are the opponents of the last, and retract the tongue. Leaving the other parts of the anatomy, we beg the reader's attention to the action of the muscle c c c, which presents one of those curious instances observed in comparative anatomy, of a mechanism adapted to a particular purpose; the tongue is not only thrust out far by this apparatus, but it is shot with great rapidity, in correspondence with its barbed point; this effect is produced by the two extremities of the muscle being fixed points, and the fibres of the muscle itself running on the concave side of the cartilaginous bow, so as to form a smaller circle. We require no mathematical demonstration to prove, that the tongue must be thrust out to a greater distance than the measure of contraction of the muscle. Let us tie the line of the fishing-rod to the last ring of its slender top, and pull upon it at the last ring of the butt: the motion of the top will be very extensive, even when only an inch of the line is drawn through the rings. This is a pretty accurate representation of what takes place by the contraction of this protruding muscle. We have noticed that the upper end of this arch is fixed, the whole motion must therefore be given to the loose extremity in the tongue; and we cannot but observe, that whilst this peculiar arch and muscular ring are adapted for the rapid protrusion of the tongue, its retraction is produced by a common muscle, that is, a muscle running in a straight course. Another curious part of this apparatus is, that a very large gland, which pours out a glutinous matter, is embraced, and compressed by the action of the circular muscle. This viscid secretion bedewing the tongue furnishes an additional means for the bird to pick up insects, such as ants, without the necessity of sticking each with its arrow. Nothing can be more mechanical, or more happily adapted to its purpose, than the whole of this structure, and consequently nothing better suited to strengthen our argument. Indeed, it is not inferior to the means employed for giving rapidity of motion to the membrana nictitans of the eye of the bird.
With the instrument, as we have before hinted, we should ex
pect a particular instinctive action, and a corresponding muscular power. As an animal with horns has a powerful neck, so
has the neck of the heron, introduced here, an extraordinary muscular power, without which, indeed, the long and sharp bill would be of little use. When the dog approaches the wounded heron, the bird throws itself upon its back, and, retracting its long neck, suddenly darts it out with a force which strikes the bill deep into the dog. If you
hold your hat towards the bird, the bill will be struck quite through it. In contending with the hawk, when the latter is spitted, it is not by the rapid descent of the hawk, but by the force with which the heron drives its bill. The strength of the bill of the parrot, and that of all birds which break the stones of fruit or nuts, or hard seeds, is in another direction: the bill is hooked, yet is differently formed from that of the carnivorous bird. The intention is, in the first place, that the point shall play vertically, which, with the strengthening by successive layers of the horny material of the bill
near the point, enables it to break hard objects; and secondly, that by this form the nut or seed may be brought nearer the