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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 preda-. tory 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 encounter 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 fishes is so great, as to overturn the systems that have attempted to account for it on those principles; that by some power in the stomach yet unknown, which from all kinds of artificial maceration acts differently, the meat
taken into the Maw is often seen, although nearly digested, still to retain its original form, and whilst ready for a total dissolution, appears to the Eye as yet untouched by the force of the Stomach.
The power of fishes to sustain themselves upon a given quantity of food, seems to accommodate itself to the quantity of aliment with which they are supplied. A Pike, sparingly fed, can be habituated to subsist on very little aliment; if fully dieted, it acquires the power of devouring an hundred Roaches in three days. Exceptions are produced by Naturalists, to the extraordinary Voraciousness of fishes; but if thoroughly examined, they will perhaps be found more apparent than real. Some are said to subsist on pure water alone; the Element of Water, however, is seldom found unmixed; the very Epithets usually applied to it of salt, bitter, sweet, imply a composition perceptible even to the taste; the particles of the Earth upon which it runs necessarily enter into it, and vitiate its Purity; these substances, together with myriads of Animalcules with which it teems, may for a while afford a scanty subsistence, and sustain the being of the most hungry animals. Of the Economy of Nature, we are, in fact, only capable of observing a few of the visible effects, and the Phenomena resulting from them in certain circumstances: we cannot prove that fishes may not be naturally endowed with the Faculty of converting unorganized matter, that may at this moment subsist under a fluid form, into solid animal substances. We are certain that a Leech may be long preserved healthy in common water, will in
crease in size, and be capable of exercising all its animal functions in that state. It would be hard to deny that the Leech had in this instance derived nourishment from the fluid alone in which it lives, though it is well known, that the Leech greedily sucks up another fluid of Animal origin, when it can have access to that, from which we cannot doubt, but it receives nourishment; from this may be inferred, that fishes in general can obtain sustenance from pure water, in the same manner as terrestrial animals derive it from Vegetables, and though in both cases there may be some kinds which cannot be at all subsisted upon this original pabulum in its native state, yet this pabulum must be considered as constituting either directly or indirectly the food of the whole; so that the flesh of all terrestrial animals may be considered as being produced from vegetable matter, changed by the animal process into its present state. In like manner, the flesh of all fishes may be deemed to be water (or some diaphanous matter administered through the medium of water) converted by the animal economy into the flesh of fishes; and vegetable substances also, from something administered to them in a similar way, through the medium of water, may be held to derive their Nourishment.
Supposing then that fishes, perhaps of every sort, procure some part of their sustenance from water, yet of all known to Man as an article of food, not one it is conceived subsists so entirely on water as the Herring; and there is little reason to doubt, but that Herrings extract their subsistence from
water, nearly as much as vegetables in general do. The Herring is always found in Shoals, and on some occasions are crowded so close together, as to fill the Sea, at least so far as our implements can reach from top to bottom. Ships are said to have been retarded in their course in passing through these Shoals, and instances are recorded where these little fishes have been left by the Ebbing of the tide in heaps three feet deep upon the shores for many miles in extent. It is universally credited among those conversant in the Herring Fishery, that no other Fish will go into the middle of a Shoal. The Whale, to whom they are a favourite repast, and who swallows a thousand at once, never ventures into the Shoal, but hovers about the skirts of it, and regularly follows their course. The Dog-fish, which in vast troops assiduously attend the Herrings wherever they go, carefully keep aloof from the great Mass of them; so it is with other fishes, who delight in the Herring as a prey, but as a body seem to dread their Multitudes. That Herrings obtain their subsistence directly from Water in which they swim, seems confirmed by many facts respecting the habits of that singular and celebrated fish. Although ever swimming in Shoals, unlike any other Phenomenon in Nature with which man is acquainted, unless it be those destructive swarms of Locusts which, in certain Regions, have been sometimes known so to fill the Air as to obscure the light of the Sun, and cover with their bodies every terrestrial object they met with in their course; yet no other resemblance can be found be