provifion for them, as any other bird. She does not leave her egg in every

hole.

The falmon fuffers no furmountable obftacle to oppofe her progress up the ftream of fresh rivers. And what does he do there? She sheds a spawn, which the immediately quits, in order to return to the fea; and this iffue of her body she never afterwards recognizes in any shape whatever. Where shall we find a motive for her efforts, and her perseverance? Shall we feek it in argumentation, or in instinct? The violet crab of Jamaica performs a fatiguing march, of some months continuance, from the mountains to the fea-fide. When the reaches the coaft, fhe cafts her fpawn into the open fea; and fets out upon her return home.

Moths and butterflies, as hath already been observed, feek out for their eggs, thofe precife fituations and fubftances, in which the offspring caterpillar will find its appropriate food. That dear caterpillar the parent butterfly must never fee. There are no experiments to prove that she would retain any knowledge of it, if fhe did. How fhall we account for her conduct? I do not mean for her art and judgment in felecting and fecuring a mainte

nance

nance for her young, but for the impulse upon which the acts. What fhould induce her to exert any art, or judgment, or choice, about the matter? The undifclofed grub, the animal, which the is deftined not to know, can hardly be the object of a particular affection, . if we deny the influence of inftinct. There is nothing, therefore, left to her, but that, of which her nature feems incapable, an abstrac anxiety for the general prefervation of the fpecies; a kind of patriotifm; a folicitude left the butterfly race fhould ceafe from the creation. :

Laftly; the principle of affociation will not explain the discontinuance of the affection when the young animal is grown up. Affociation, operating in its ufual way, would rather produce a contrary effect. The object. would become more neceffary by habits of fociety: whereas birds and beasts, after a certain time, banish their offspring; difown their acquaintance; feem to have even no knowledge of the objects which fo lately engrossed the attention of their minds, and occupie dthe industry and labour of their bodies. This change, in different animals, takes place at different distances of time from the birth; but the time always correfponds with the ability

of

of the young animal to maintain itself; never anticipates it. In the fparrow tribe, when it is perceived that the young brood can fly and -fhift for themselves, then the parents forfake them for ever; and, though they continue to live together, pay them no more attention than they do to other birds in the fame flock. I believe the fame thing is true of all grega rious quadrupeds.

In this part of the cafe the variety of re*fources, expedients, and materials, which ani mals of the fame fpecies are faid to have recourse to, under different circumstances, and when differently fupplied, makes nothing against the doctrine of inftincts. The thing which we want to account for is the propenfity. The propenfity being there, it is probable enough that it may put the animal upon - different actions according to different exigences. And this adaptation of resources may look like the effect of art and confideration, rather than of inftinct; but ftill the propensity is inftinctive. For inftance, fuppose what is related of the woodpecker to be true, that, in Europe, the depofits her eggs in cavities,

* Goldsmith's Nat. Hist. vol. iv. p. 244.

which the fcoops out in the trunks of foft or decayed trees, and in which cavities the eggs lie concealed from the eye, and in some fort fafe from the hand, of man; but that, in the forefts of Guinea and the Brafils, which man feldom frequents, the fame bird hangs her neft to the twigs of tall trees; thereby placing them out of the reach of monkeys and Snakes, i. e. that in each fituation fhe prepares against the danger which she has most occasion to apprehend: suppose, I say, this to be true, and to be alledged, on the part of the bird that builds these nefts, as evidence of a reasoning and distinguishing precaution, still the question returns, whence the propenfity to build at

all?

Nor does parental affection accompany generation by any univerfal law of animal organization, if fuch a thing were intelligible. Some animals cherish their progeny with the most ardent fondness, and the most affiduous attention; others entirely neglect them: and this distinction always meets the conftitution of the young animal, with refpect to its wants and capacities. In many, the parental care extends to the young animal; in others, as in all oviparous fish, it is confined to the egg,

and even, as to that, to the disposal of it in its proper element. Alfo, as there is generation without parental affection, fo is there parental instinct, or what exactly resembles it, without generation. In the bee tribe, the grub is nurtured neither by the father nor the mother, but by the neutral bee. Probably the cafe is the fame with ants.

I am not ignorant of a theory, which refolves instinct into fenfation; which afferts, that what appears to have a view and relation to the future, is the refult only of the prefent difpofition of the animal's body, and of pleafure or pain experienced at the time. Thus the incubation of eggs is accounted for by the pleasure which the bird is fupposed to receive from the pressure of the fmooth convex surface of the fhells against the abdomen, or by the relief which the mild temperature of the egg may afford to the heat of the lower part of the body, which is obferved at this time to be increafed beyond its ufual state. This prefent gratification is the only motive with the hen for fitting upon her neft: the hatching of the chickens is, with respect to her, an accidental confequence. The affection of viviparous animals for their young, is in like

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manner