bones, and in the Pike, which has two cavities, in one of them is found two bones, and in the other, one; in the Ray there is only a chalky substance; this chalky substance is also found in the Ears of amphibious Animals.

In some fishes, the external communication enters at the union of the two perpendicular canals; this is the case with all the Ray species; the external orifice being small, and placed on the upper flat surface of the head; but it is not every genus of fishes that has the outward opening. The nerves of the Ear pass outwards from the brain, and appear to terminate at once on the external surface of the swelling of the semi-circular tubes above described. They do not seem to pass. through them so as to get on the inside, as is supposed to be the case in Quadrupeds; it is therefore to be much suspected, that the lining of the tubes in the Quadruped is not Nerve, but a kind of internal Periosteum.

Fishes thus evidently possessing the Organ of hearing, precludes the necessity of making any Experiment, which only leads to prove this fact. One trial will however be related, to shew that Sound affects them, and is one of their Guards, as it is in other animals.

"When in Portugal, in 1762, (says Mr. H.) I observed in a Nobleman's garden near Lisbon, a small fish-pond full of different sorts of fish. Its bottom was level with the ground, and was made by forming a bank all round, with a Shrubbery close to it; whilst lying on the bank seeing the fish, I desired a Gentleman who was my companion, to go behind the Shrubs (that there might be no reflection of light from the flash) and fire his gun. The moment the report was made, the fish seemed to be uniformly affected, for they vanished immediately, raising as it were a cloud of mud from the bottom. In about five minutes afterwards they began to appear, and again swam about as before."

Mr. HUNTER allows, that altho' GEOFFROI, who wrote upon this topic, cannot be said to have given a perfect account of the Organ of hearing in fishes, yet he should be considered as a discoverer, and with great modesty Mr. H. continues, that he should not have claimed a discovery, to which Mr. GEOFFROI had a prior right, had he been acquainted with that Author's researches and pretensions. The hearing of fishes has been long and strongly contended, but by the skilful investigation of our celebrated Anatomist, the Question of the fishes Hearing, seems to be decided.

The Sight of fishes is perhaps the most perfect of all their senses, and yet their seeing is far inferior to that of most other animals, the Eye in almost all fish is covered with the same transparent skin that surrounds the rest of the head; and which probably defends it in the water, as they are without Eye-lids; the globe is more depressed in front, and is furnished behind with a muscle, which serves to lengthen or flatten it according to the animal's necessities. The Chrystalline humour which in Quadrupeds is flat, and of the shape of a button mould, in fishes is round as a pea, or sometimes oblong like an Egg. A general idea of this may be formed from the glasses used by near-sighted people; those whose Chrystalline humour is too conver, or in other words, too round, are always very near-sighted, and have recourse to concave glasses to amend this imperfection of Nature. The Chrystalline humour of fish is so round, that it is not in the power of glasses, much less of water, to correct their vision. This humour in fishes is that hard pea-like substance which is found in their Eyes after boiling; in the natural state, it is transparent, and not much harder than a Jelly. There is no evidence of any fishes seeing at a considerable distance, and the conduct of many of them, that are deceived by the different baits prepared in imitation of their food, gives room to suspect, that objects are not very distinctly perceived by them, even when near.

In all animals, Respiration, or the admission of Air into the body, seems necessary to the support of life; in the spinous fishes, which are

more immediately the objects within our notice, respiration is performed by the Gills, without the cavity of the body; but the precise manner in which this operation is carried on, is one of those secrets of Nature, which neither the Glasses nor the Knife of the Anatomist have ever yet been able to develope. Those who have seen a fish in water, will recollect the motion of its Lips and Gills, or at least of the bones on each side that cover them; in the animal, this motion is doubtless analogous to our breathing, but it is not Air, but Water, that the fish actually sucks in and spouts out through the gills at every motion, while the bony covering of the gills prevents it from going through them until the animal has drawn the proper quantity of Air from the body of water there imprisoned, the bony covers then open, and give it a free passage; the gills, by this means, are again opened, and a fresh quantity of water is admitted. Should the fish be obstructed in the free play of its gills, or the bony covers, by a string tied round them, be kept from moving, the animal would speedily be convulsed, and die in a few minutes. The manner indeed whereby the Air is transmitted from the Lungs of Quadrupeds into the blood, is perhaps equally mysterious, as its passage from the Gills of fishes into the arteries leading to the heart. As the Air and Water pass quickly through the gills, without any apparent effort to separate them, probably but a small quantity of the former is absorbed, but, by the frequent transition of the water, a sufficiency of it may be admitted, to supply animals. whose blood is not in great abundance, and is naturally cold.

But however small a quantity of Air may suffice to sustain the life of a fish, some portion is absolutely essential to every living being; the Death of fish in a severe frost is in consequence of the congelation of the surface, whereby the external Air is excluded, the animals below must of course perish; and the eagerness to procure a supply of Air is manifested, by the suffocating fish instantly crowding to any aperture made in the Ice, where, to obtain it, they will suffer themselves to be caught by the hand.

Next to the necessity of breathing air, that of devouring food seems to be the most urgent and constant in the constitution of fishes. Among them, both in strength and avidity, this appetite surpasses those boundaries, which, in the other orders of the animal world, Nature seems to have prescribed. Every aquatic animal that has life, falls a victim to the indiscriminate voracity of one or other of the fishes. Insects, Worms, or the Spawn of other tenants of the Waters, sustain the smaller tribes, which in their turn, are pursued by Millions larger and more rapacious. A few feed upon Mud, aquatic Plants, or grains of Corn, but the far greater numbers subsist upon animal food alone, and of this they are so ravenous, as to spare not those of their own kind. That there are Vegetables in both fresh and salt waters, admits no doubt, and these may furnish food to particular fishes; but those sorts are few, perhaps no one kind can be pointed out, that subsists entirely upon them; and altho' most fishes eat Flies and terrestrial Worms when they come in their way, yet in the immeasurable Waste of Waters surrounding this Globe, the swarms of fishes are so immense, that the subsistence to be derived from the above sources, appears to be altogether disproportioned to their wants, and those of a smaller size seem to constitute the principal food of nearly all the fishes known to us. Charr kept in a pond, if scantily supplied, frequently devour their own young; other fish that are larger, go in quest of more bulky prey; it matters not of what sort, whether of their own or of another Species. If we turn our attention in this argument to Sea fish, those with the most capacious mouths, pursue almost every thing that exists, and often meet each other in fierce opposition, when the fish which has the widest throat comes off with victory, and devours his Antagonist.

The voracious fishes differ widely from the predatory kinds of terrestrial animals; they are neither limited in their number, nor solitary in their habits; their rapacity is not confined to a few species, one region of the Sea, or individual efforts; almost the whole order is continually irritated by the cravings of an appetite, which excites them to en

counter every danger, and which, by its excess, often destroys that existence, which it was intended to prolong. Innumerable shoals of one species, pursue those of another, through vast tracts of the Ocean, from the vicinity of the Pole to the Equator. The Cod pursues the Whiting, which flies before it from the banks of Newfoundland, to the southern coasts of Spain. The Cachalot drives whole armies of Herrings from the regions of the North, devouring at every instant, thousands in the rear. Hence the life of every fish, from the smallest to the greatest, is but a continued scene of rapine, and every quarter of the immense Deep presents one uniform picture of hostility, violence, and invasion.

In these conflicts, occasioned by the voracity of the different kinds of fishes, the smaller classes must have long since fallen victims to the avidity of the larger, had not Nature skilfully proportioned the means of their escape, their numbers, and their productive powers, to the extent and variety of the dangers to which they are unceasingly exposed. To supply the constant waste, occasioned by their destruction in the unequal combat, they are not only more numerous and prolific than the larger species, but by a happy instinct are directed to seek for food and protection near the Shore, where, from the shallowness of the water, their Foes are unable to pursue them. These, however, yielding to the strong impulse of hunger, become plunderers in their turn, and revenge the injuries committed on their kind, by destroying the spawn of the greater fishes, which they find floating upon the surface of the water.

In what manner Digestion to such an amazing extent and rapidity is carried on in the stomach of fishes, the enquiries of Naturalists have at present been unable to ascertain; it so far exceeds every thing that can be effected either by Trituration, the operation of Heat, or of a dissolving fluid, that a celebrated Physician (Dr. HUNTER), after various experiments, was of opinion, that none of these causes were equal to the effect, and that the digestive force in the cold Maw of