gan; between the mechanical operation, and the chymical process.

II. The relation of the kidneys to the bladder, and of the ureters to both, i. e. of the fecreting organ to the veffel receiving the fecreted liquor, and the pipe laid from one to the other for the purpose of conveying it from one to the other, is as manifest as it is amongst the different veffels employed in a diftillery, or in the communications between them. The animal ftructure, in this cafe, being fimple, and the parts easily separated, it forms an instance of correlation which may be presented by diffection to every eye, or which, indeed, without diffection is capable of being apprehended by every understanding. This correlation of inftruments to one another fixes intention fomewhere.

Efpecially when every other folution is negatived by the conformation. If the bladder had been merely an expanfion of the ureter, produced by retention of the fluid, there ought to have been a bladder for each ureter. One receptacle, fed by two pipes, iffuing from different fides of the body, yet from both conveying the fame fluid, is not to

be accounted for by any fuch fuppofition as this.

III. Relation of parts to one another accompanies us throughout the whole animal œconomy. Can any relation be more fimple, yet more convincing, than this, that the eyes are fo placed as to look in the direction in which the legs move and the hands work? It might have happened very differently, if it had been left to chance. There were, at least, three quarters of the compass out of four to have erred in. Any confiderable alteration in the position of the eye, or the figure of the joints, would have disturbed the line, and deftroyed the alliance between the sense and the limbs.

IV. But relation perhaps is never so striking as when it fubfifts, not between different parts of the fame thing, but between different things. The relation between a lock and a key is more obvious, than it is between different parts of the lock. A bow was defigned for an arrow, and an arrow for a bow; and the defign is more evident for their being separate implements.

Nor do the works of the Deity want this

clearest

cleareft fpecies of relation. The Sexes are manifeftly made for each other. They form the grand relation of animated nature; univerfal, organic, mechanical; fubfifting, like the clearest relations of art, in different individuals; unequivocal, inexplicable without defign:

So much fo, that, were every other proof of contrivance in nature dubious or obfcure, this alone would be fufficient. The example is complete. Nothing is wanting to the argument. I fee no way whatever of getting

over it.

V. The teats of animals, which give fuck, bear a relation to the mouth of the fuckling progeny; particularly to the lips and tongue. Here alfo, as before, is a correspondency of parts; which parts fubfift in different individuals.

THESE are general relations, or the relations of parts which are found, either in all animals, or in large claffes and descriptions of animals. Particular relations, or the relations which fubfift between the particular configuration of one or more parts of certain fpecies of animals, and the particular configuration of one or more other parts of the fame

animal, which is the fort of relation, that is, perhaps, most striking,) are such as the fol lowing.

I. In the fwan; the web foot, the spoon bill, the long neck, the thick down, the graminivorous ftomach, bear all a relation to one another, inasmuch as they all concur in one defign, that of fupplying the occafions of an aquatic fowl, floating upon the surface of fhallow pools of water, and feeking its food at the bottom. Begin with any one of these particularities of ftructure, and observe how the reft follow it. The web foot qualifies the bird for fwimming; the spoon bill enables it to graze. But how is an animal, floating upon the furface of pools of water, to graze at the bottom, except by the mediation of a long neck? A long neck accordingly is given to it. Again, a warm-blooded animal, which was to pass its life upon water, required a defence against the coldnefs of that element. Such a defence is furnished to the fwan, in the muff in which its body is wrapped. But all this outward apparatus would have been in vain, if the intestinal fyftem had not been fuited to the digestion of vegetable substances.

I fay fuited to the digeftion of vegetable fubftances: for it is well known, that there are two intestinal fyftems found in birds, one with a membranous ftomach and a gaftric juice, capable of diffolving animal fubftances alone; the other with a crop and gizzard, calculated for the moistening, bruifing, and afterwards digeffing, of vegetable aliment.

Or fet off with any other diftinctive part in the body of the fwan; for inftance, with the long neck. The long neck, without the web foot, would have been an incumbrance to the bird; yet there is no neceffary connection between a long neck and a web foot. In fact they do not usually go together. How happens it, therefore, that they meet, only when a particular defign demands the aid of both?

II. This mutual relation, arifing from a fubferviency to a common purpose, is very obfervable also in the parts of a mole. The strong short legs of that animal, the palmated feet armed with fharp nails, the piglike nofe, the teeth, the velvet coat, the small external ear, the fagacious fmell, the funk protected eye, all conduce to the utilities, or to the fafety,