the left or right is accomplished. It is supposed the swimming bladder aids the fishes motion; and that they can dilate or contract this Organ, and by that means raise or sink themselves at pleasure, by increasing or diminishing the specific gravity of their body; and as their watery Element is of different degrees of weight, according to its depth, they thus possess a power of varying their specific gravity, of swimming easily at a great depth, and of poising themselves in any part of it it is however insisted, that the bladder cannot be thus employed, as it has no Muscles to enable the fish voluntarily to shrink or expand it. Many fish that live continually at the bottom of the water, have an air bladder, such as the Eel and the Flounder; and many are entirely without any, that swim at ease in every depth, for instance the Gudgeon. Naturalists have assigned different uses to this bladder, and altho' it is possible, that some one, or more than a single purpose, foreign from their Ideas, may be served by it, the Apparatus is too conspicuous to be formed in vain.

Fishes thus fitted by their internal structure, and outward shape, for their Element, seem equally well furnished with the means of happiness, as either Birds or Quadrupeds. Like them, they are furnished with an external covering to defend them from the injurious turbulence of the fluid which they inhabit; that slimy substance which is secreted from the pores of all fishes, not only defends their bodies from accidents, but to their progress through the water, it happily presents no obstruction; besides this substance, the greater part of fishes have a strong covering of scales, which is a still further protection from injury, and beneath this, an oily matter is supplied, which preserves the body in warmth and vigour. When, however, the Senses and other faculties of this part of the Animal Kingdom are examined, we find that Nature having intended them for less perfect beings, in her endowments has been proportionably sparing. The Brain, the seat of sensation, is much smaller in fishes than in other animals. Their sense of Touch is, in all probability, far from being delicate, being obstructed by those strong teguments which surround them.. The external.

Organs of Smell, and the nerves supplying them, are perceptible in the greater part of fishes; but as Air is the only medium we know for the distribution of Odours, it cannot be supposed that residing in water, they can possess any capacity of being affected by them; if they have any perception of smells, it must be that the Olfactory membrane in fishes, serves them instead of a distinguishing palate, in the same manner as we distinguish by our taste; by this use of the Organ, they may judge of substances, when Vapours, having tinctured the water, are sent to their nostrils, and doubtless produce some kind of sensation, as otherwise they would be provided with the instruments of a Sense, which from want of an opportunity of using, they could not enjoy.

The sense of Taste in fishes must be very imperfect, if its delicacy arises from the softness of the Organ, the whole mouth of most fishes being covered with a hard bony substance, by which they are deprived of almost all power of discriminating different bodies by the Palate, insomuch, that the salt-water fishes have been known to swallow the fishermen's plummet, instead of the bait. The greediness which Sea fish discover, and by which they are taken, is prodigious; the lines of the fishermen who go off to sea, are coarse and clumsy, their baits are seldom more than a piece of a fish, or the flesh of some quadruped, stuck on the hook in a bungling manner; on the banks of Newfoundland, the hook, which is only hid by the entrails of the animal last taken, is dropt into the water, the Cod seizes it at once, and the fishermen have but to pull up as fast as they throw down; but it is otherwise in fresh water, the lines must be drawn to a hair-like fineness, be tinctured of the peculiar colour of the stream, the bait must be selected with care, or formed with the nicest art, and still the fishes approach with diffidence, and often swim round it with disdain, while hours are waited in fruitless expectation, and the Patience of an Angler is become proverbial.

Of the sense of Hearing, it is probable, fish are altogether destitute, since all, except the Cetaceous, are deprived not only of external Ears,

but also of the auditory Nerves and Canal; for these reasons, it is generally agreed by Naturalists, that all the Spinous fishes (so called from their bones resembling the sharpness of Thorns) have no faculty of hearing. In this class of the Animal Kingdom, LINNEUS, whose accuracy in examining a great number of subjects, is scarcely to be disputed, confesses, that he has been unable to discover any auditory Organs. Had nature made a provision in their conformation for the hearing of fishes, that sense must, by the properties of the Element which they inhabit, have been rendered extremely imperfect. Experiments on the capacity of water to transmit Sounds, have been correctly tried, and as it quickly deadens that vibration upon which they depend, it is unable to convey them but a short distance. A man whose head is one foot beneath the surface, hears voices and words uttered in the Air, but when immersed twelve feet, he scarcely hears a musquet discharged over his head; hence it is probable, that Nature having for ever consigned Fishes to an Element, which must in a great measure have defeated its purpose, has formed no Organic Apparatus to convey sounds.

to them.

On the contrary side several of the old Naturalists allege, in proof of the faculty of hearing in fishes, that in some places in Germany where they are tamed, they are regularly convened to their food by the sound of a Bell; but Mr. GoUAN, of Montpelier, clearly refutes these proofs. The Gold-fishes which he kept in Vases, could never be disturbed by the loudest noise, provided he could prevent the tremor of the Air from affecting the Water. From this it appears, that fishes can no more hear than speak, and that apparently coming to their food at the call of a bell or whistle, it is either by feeling the sound vibrate and affect the water, or by seeing the persons approach by whom their food is accustomed to be given, that they collect themselves together to receive it.

Upon this Organ of hearing in fishes, the late Mr. JOHN HUNTER

observes very differently, and his Authority warrants the digression in giving his arguments at some length.

He states, that previous to his quitting his Anatomical pursuits, in the year 1760, and going with the Army to Bellisle, he had found this Organ in fishes, and had the parts exposed and preserved in spirits. My researches, continues Mr. H. have been continued ever since that time, yet I am still inclined to consider whatever is uncommon in the structure of these parts in fishes, as only one mode in the variety displayed in the formation of this Organ of sense in different animals, descending in regular progression from the most perfect to the most imperfect. The preparations to illustrate these facts have ever since been exhibited in my Collection to both the curious of this Country and Foreigners in shewing whatever was .new, or supposed to be so, the Ears of Fishes were always considered by me as one important article.

The Organ of hearing in fishes is placed on the sides of the Skull or cavity which contains the Brain; but the Skull makes no part of the Organ, as it does in the Quadruped and the Bird, the Organ itself being distinct and detached. In some fishes, the Organ is wholly surrounded by the parts composing the Cavity of the skull, as in the Ray kind. In others, this Organ is partly within the skull, or that cavity containing the brain, as in the Salmon, Cod, &c. the skull projecting laterally, and forming a Cavity.

The Organ of hearing in fishes appears to increase with the Animal, for it is nearly in the same proportion with that of the Animal, which is not the case with the Quadruped, &c. the Organs being in them nearly as large in the growing foetus, as in the adult.

It is much more simple in fishes than in all those orders of animals which may be reckoned superior, such as Quadrupeds, Birds, and

Amphibious animals; but there is a regular gradation from the first of these to Fishes. It varies in different orders of Fishes; but in all consists of three curved tubes which unite with one another; this union forms in some, only one canal, as in the Cod, Salmon, Ling, &c.; and in others a pretty large cavity, as in the Ray kind. In the Jack or Pike, there is an oblong bag, or blind process, which is an addition to these canals, and which communicates with them at their union. In the Cod, &c. this union of the three tubes stands upon an oval cavity, and in the Jack there are two; the additional cavities in them, appear to answer the same purpose with the cavity in the Ray or cartilaginous fishes, which is the union of the same canals.

The whole Organ is composed of a kind of cartilaginous substance, very hard or firm in parts, and which in some fishes, is crusted over with a thin bony lamella, so as not to allow it to collapse; for as the skull does not form any part of these canals or cavities, they must be composed of a substance capable of keeping its form.

Each tube describes more than a semicircle. This resembles in some respect what is found in most other animals, but differs in the parts being distinct from the skull. The Turtle and the Crocodile have a structure somewhat similar to this; and the intention is the same, for their skulls make no part of the Organ. Two of the semi-circular canals are similar; they may be called a pair, and are placed perpendicularly, and united at one end laterally, forming one canal; at their other extremities they have no connection with each other, but are joined to the terminations of the horizontal one near its entrance into the common cavity; the third is not so long; in some it is horizontal, uniting, as it were, the other two at their ends. In the Skate it is only united to one of the perpendicular canals; near the union of these canals into the common, they are swelled into round bags, becoming then much larger. In the Ray kind they all terminate in one cavity; and in the Cod, in one canal placed upon the additional cavity or cavities, in which there is a bone or bones. In some there are two