populous countries, and are too often unwelcome intruders upon the fruits of human labours. In making their nests, therefore, the little birds use every art to conceal them from man, while the great birds use every precaution to render their's inacessible to wild beasts, or vermin. The unerring instinct which guides every species in contriving the most proper habitation for hatching their young, demands our observation. In hot tropical climates nests of the same kind are made with less art, and of less warm materials, than in the temperate zone, for the sun in some measure assists the business of incubation. In general, however, they build them with great art, and line them with such substances as keep or communicate warmth to their eggs. Nothing can exceed their patience while hatching; neither the calls of hunger, nor the near approach of danger could drive them from the nest; and though they have been found fat upon beginning to sit, yet before the incubation is over the female is usually wasted to a skeleton. The male ravens and crows, while the hens are sitting, take care to provide them with food; while other birds, such as pigeons and sparrows, take their turns, the male relieving the female at proper intervals. Sometimes, however, the eggs acquire a degree of heat too great for the purposes of hatching; in such cases, the hen leaves them to cool a little, and then returns with her usual perseverance and pleasure. When the young brood comes forth, nothing can exceed the industry and the seeming pride of the parents; the most timid becomes courageous in their defence; and 'provides them with food proper for their age or kind. Birds of the rapacious kind become at this season more than ordinarily ravenous, and those of the granivorous sorts discontinue their singing, entirely taken up in procuring subsistence for their young.

Of all birds the ostrich is the greatest, and the American humming bird the least. In these the gradations of nature

are strongly marked, for the ostrich in some respects approaches the nature of that class of animals immediately placed above him, namely quadrupeds, being covered with hair, and incapable of flying; while the humming bird, on the other hand, approaches that of insects. These extremities of the species, however, are rather objects of human curiosity than use; it is the middle orders of birds, which man has taken care to propagate and maintain; these largely administer to his necessities and pleasure, and some birds are even capable of attachment to the person that feeds them. How far they may be instructed by long assiduity, is obvious from a late instance of a canary bird, which was shewn in London, and which had been taught to pick up the letters of the alphabet at the word of command. Upon the whole, however, they are inferior to quadrupeds in their sagacity; they are possessed of fewer of those powers which look like reason, and seem, in all their actions, rather impelled by instinct than guided by choice. (1)

(1) ["Having thus given a short history of Birds, I own I cannot take leave of this most beautiful part of the creation without reluctance. These splendid inhabitants of air possess all those qualities that can sooth the heart and cheer the fancy. The brightest colours, the roundest forms, the most active manners, and the sweetest music. In sending the imagination in pursuit of these, in following them to the chirruping grove, the screaming precipice, or the glassy deep, the mind naturally lost the sense of its own situation, and, attentive to their little sports, almost forgot the task of describing them. Innocently to amuse the imagination in pursuit of these is wisdom; and nothing is useless that, by furnishing mental employment, keeps us for a while in oblivion of those stronger appetites that lead to evil. But every rank or state of mankind may find something to imitate in those delightful songsters, and we may not only employ the time, but mend our lives by the contemplation. From their courage in defence of their young, and their assiduty in incubation, the coward may learn to be brave, and the rash to be patient. The inviolable attachment of some to their companions may give lessons of fidelity; and the connubial tenderness of others be a monitor to the incontinent. Even those that are tyrants by nature never spread capricious destruction; and, unlike man, never inflict a pain but when urged by necessity.”—Animated Nature, vol. vi. p. 148.]

PART III.-OF FISHES.

THE productions of nature, as they become less perfect, grow more numerous. When we consider what numberless sorts have hitherto escaped human curiosity, what a variety of Fishes are already known, and the amazing fecundity of which they are possessed, we are almost induced to wonder how the ocean finds room for its inhabitants. A single fish is capable of producing eight or ten millions of its kind in a season; but nature has happily obviated this hurtful increase, by making the subsistence of one species depend on the destruction of another. The same enmities that subsist among land animals prevail with equal fury in the waters, and with this aggravation, that by land the rapacious kinds seldom devour each other, but in the ocean it seems an universal warfare of each against each. The large devour the small even of their own species, and these, in their turn, become the tyrants of such as they are able to destroy.

Fishes in general may be divided into those that breathe through lungs, and have red blood circulating through their veins; and those that respire through the gills, and whose circulating juices are limpid and colourless. The first sort, which comprehends all of the cetaceous or whale kind, are possessed of a greater degree of heat than the element they inhabit, are frequently obliged to come to the surface of the water to respire fresh air, and, though they are properly inhabitants of the ocean yet are capable of being suffocated in it. They use coition, bring forth their young alive, nourish them with their milk, and resemble quadrupeds as to their internal conformation. The latter sort, on the contrary, are as cold as the element in which

they live, they breathe only in the water, they produce by spawn which is impregnated by the male, and are for the most part covered with scales. Between these there is yet an intermediate kind, which is called the cartaliginous. These breathe through the gills like the latter, and bring forth their young alive like the former. Instead of bones, their muscles are supported only by cartilages, or gristles, and from this conformation they continue to grow larger as they grow older; for, different from every other animal, their bones never acquire such a certain degree of hardness as to hinder their future growth.

The number of the cetaceous and cartilaginous kind, however, is but small when compared to the other kind already described, in which are to be found a greater quantity of small bones, which serve to strengthen and support the muscles. The bones of a single carp, for instance, amount to four thousand three hundred and eighty-six. These are the kinds generally to be found in fresh water; these have been most frequently subject to human inspection, and from them our descriptions are more usually taken.

The shape of most fish is much alike, sharp at either end, and swelling in the middle, by which they are thus able to traverse the fluid they inhabit with greater ease. That peculiar shape which nature has granted most fishes we endeavour to imitate in such vessels as are designed to sail with the greatest swiftness; however, the progress of a machine moved forward in the water by human contrivance is nothing to the rapidity of an animal destined to reside there. The shark overtakes a ship in full sail with ease, plays round it, and abandons it at pleasure. The tail of all fish is extremely flexible, and furnished with muscles that take up near a third part of the whole body. In this lies their greatest strength, and by bending it to the right or left they repel the water behind, and advance with the

desired swiftness. The motion of this is in some measure assisted by the fins, but their chief use is to poise the body, and at will to stop its motion. This is proved by experience; for when the fins are cut off, the fish reels to and fro, no longer able to keep its natural posture. These therefore only keep the fish steady; when it would turn to the right it moves the fins on the left side, when to the left it plays those on the right; the tail, however, is the grand instrument of progressive motion.

As all animals that live upon earth, or in the air, are furnished with a proper covering to keep off external injury, so all that live in the water are covered with a slimy glutinous matter, that, like a sheath, defends their bodies from the immediate contact of the surrounding fluid. Beneath this is generally found a coat consisting of strong scales, and under that, before we come to the muscular parts of the body, an oily substance, which supplies the requisite warmth and vigour.

When we examine a fish's scale through a microscope, it is found to consist of a number of concentrical circles, one within the other, in some measure resembling those which appear upon the transverse section of a tree, and, in fact, offering the same information. For, as in trees we can tell their age by the number of their circles, so in fishes we can tell their's by the number of circles in every scale, reckoning one ring for every year of the animal's existence. M. Buffon, by this method, found a carp, whose scales he examined, to be not less than a hundred years old; a thing almost incredible, had we not several accounts in other authors, which tend to confirm its veracity.

That fish are extremely long-lived, appears from the nature of the element in which they breathe; in this they are not subject to those sudden changes which terrestrial animals hourly experience; their's is an uniform existence,