the feet are adapted. The relation is manifeft, whichever of the parts related we place first in the order of our confideration. In a word: the feet of the mole are made for digging; the neck, nose, eyes, ears, and skin, are peculiarly adapted to an underground life; and this is what I call relation.

СНАР

CHAPTER XVI.

COMPENSATION.

COMPENSATION is a fpecies of relation. It is relation, when the defects of one part, or of one organ, are fupplied by the ftructure of another part, or of another organ. Thus,

I. The short, unbending neck of the elephant, is compenfated by the length and flexibility of his probofcis. He could not have reached the ground without it: or, if it be supposed that he might have fed upon the fruit, leaves, or branches of trees, how was he to drink? Should it be afked, Why is the elephant's neck fo fhort? it may be answered that the weight of a head fo heavy could not have been fupported at the end of a longer lever. To a form therefore, in fome respects neccffary, but in fome refpects alfo inadequate to the occafions of the animal, a fupplement is added, which exactly makes up the deficiency under which he laboured.

If it be fuggefted, that this probofcis may have been produced in a long course of generations, by the conftant endeavour of the elephant to thrust out his nofe, (which is the general hypothefis by which it has lately been attempted to account for the forms of animated nature,) I would afk, how was the animal to fubfift in the mean time; during the procefs; until this prolongation of fnout were completed? What was to become of the individual, whilft the species was perfecting?

Our business at prefent is, fimply to point out the relation, which this organ bears to the peculiar figure of the animal, to which it belongs. And, herein, all things correfpond. The neceffity of the elephant's probofcis arises from the shortness of his neck; the shortness of the neck is rendered neceffary by the weight of the head. Were we to enter into an examination of the ftructure and anatomy of the probofcis itfelf, we should fee in it one of the moft curious of all examples of animal mechanifm. The difpofition of the ringlets and fibres, for the purpose, firft, of forming a long cartilaginous pipe; fecondly, of contracting and lengthening that pipe; thirdly, of turning it in every direction at the will of the

animal;

animal; with the fuperaddition, at the end, of a fleshy production, of about the length and thickness of a finger, and performing the office of a finger, so as to pick up a straw from the ground; these properties of the same organ, taken together, exhibit a specimen, not only of defign, (which is attested by the advantage,) but of confummate art, and, as I may say, of elaborate preparation, in accomplishing that defign.

II. The hook in the wing of a bat, is strictly a mechanical, and, also, à compenfating contrivance, At the angle of its wing there is a bent claw, exactly in the form of a hook, by which the bat attaches itself to the fides of rocks, caves, and buildings, laying hold of crevices, joinings, chinks, and roughneffes. It hooks itself by this claw; remains fufpended by this hold; takes its flight from this pofition: which operations compenfate for the decrepitude of its legs and feet. Without her hook, the bat would be the most helpless of all animals. She can neither run upon her feet, nor raise herself from the ground. These inabilities are made up to her by the contrivance in her wing: and in placing a claw on that part, the Creator has deviated from the analogy

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analogy obferved in winged animals. A fingular defect required a fingular substitute.

III. The crane kind are to live and feek their food amongst the waters; yet, having no web feet, are incapable of swimming. To make up for this deficiency, they are furnished with long legs for wading, or long Bills for groping; or ufually with both. This is compenfation. But I think the true reflection upon the present inftance is, how every part of nature is tenanted by appropriate inhabitants. Not only is the furface of deep waters peopled by numerous tribes of birds. that swim, but marshes and fhallow pools are furnished with hardly lefs numerous tribes of birds that wade.

IV. The common parrot has, in the structure of its beak, both an inconveniency, and a compenfation for it. When I fpeak of an inconveniency, I have a view to a dilemma. which frequently occurs in the works of nature, viz. that the peculiarity of structure by which an organ is made to answer one purpofe, neceffarily unfits it for fome other pofe. This is the cafe before us. The upper bill of the parrot is fo much hooked, and so much overlaps the lower, that, if, as in other birds,

pur

the