We are not writing a fyftem of natural hiftory; therefore, we have not attended to the claffes, into which the fubjects of that fcience are diftributed. What we had to obferve concerning different fpecies of animals, fell eafily, for the moft part, within the divifions, which the courfe of our argument led us to adopt. There remain, however, fome remarks upon the infect tribe, which could not properly be introduced under any of thefe heads; and which therefore we have collected into a chapter by themfelves.

The ftructure, and the ufe of the parts, of infects, are lefs underftood than that of quadrupeds and birds, not only by reafon of their minutenefs, or the minutenefs of their parts, (for that minutenefs we can, in fome meafure, follow with glaffes) but alfo, by reafon of the remotenefs of their manners and modes of life from thofe of larger animals. For inftance, Infects, under all their varieties of form, are endowed with antennæ, which is the name given to thofe long feelers that rife from each fide of the head; but to what common ufe or want of the infect kind, a provifion fo univerfal is fubfervient, has not yet been afcertained: and it has not been afcertained, becaufe it admits not of a clear, or very probable, comparifon, with any organs which we poffefs ourfelves, or with the organs of animals which refemable ourfelves in their functions and faculties, or with which we are better acquainted than we are with infects.

Contemplatingan animal body in its collective capacity, we cannot forget to notice, what a number of inftruments are brought together, and often within how fmall a compafs. It is a clufter of contrivances. In a canary bird, for inftance, and in the fingleounce of matter which compofes his body (but which feems to be all employed), we have inftruments, for eating, for digefting, for nourifhment, for breathing, for generation, for running, for flying, for feeing, for hearing, for fmelling; each appropriate; each entirely different from all the reft.

The human, or indeed the animal frame, confidered as a mafs or affemblage, exhibits in its compofition three properties, which have long ftruck my mind, as indubitable evidences, not only of defign, but of a great deal of attention and accuracy in profecuting the defign.

I. The firft is, the exact correfpondency of the two fides of the fame animal; the right hand anfwering to the left, leg to leg, eye to eye, one fide of the countenance to the other; and with a precifion, to imitate which in any tolerable degree forms one of the difficulties of ftatuary, and requires, on the part of the artift, a conftant attention to this property of his work, diftint from every other.

It is the moft difficult thing that can be to get a wig made even; yet how feldom is the face awry?

I Can hardly imagine to myfelf a more diftinguifhing mark, and, confequently, a more certain proof of defign, than preparation, i. e. the providing of things beforehand, which are not to be ufed until a confiderable time afterwards; for this implies a contemplation of the future, which belongs only to intelligence.

Of thefe profpective contrivances the bodies of animals furnifh various examples.

I. The human teeth afford an inftance, not only of profpective contrivance, but of the completion of the contrivance being defignedly fufpended. They are formed within the gums, and there they ftop: the fact being, that their further advance to maturity would not only be ufelefs to the new-born animal, but extremely in its way; as it is evident that the act of fucking, by which it is for fome time to be nourifhed, will be performed with more eafe both to the nurfe and to the infant, whilft the infide of the mouth, and edges of the gums, are fmooth and foft, than if fet with hard pointed bones. By the time they are wanted, the teeth are ready. They have been lodged within the gums for fome months paft, but detained, as it were, in their fockets, fo long as their further protrufion would interfere with the office to which the mouth is deftined.

We proceed therefore to propofe certain examples taken out of this clafs; making choice of fuch, as, amongft thofe which have come to our knowledge, appear to be the moft ftriking, and the beft underftood; but obliged, perhaps, to poftpone both thefe recommendations to a third, that of the example being capable of explanation without plates, or figures, or technical language.

OF THE BONES

I. I challenge any man to produce, in the joints and pivots of the moft complicated, or the moft flexible, machine, that was ever contrived, a conftruction more artificial, or more evidently, artificial, than that which is feen in the vertebræ of the human neck. Two things were to be done. The head was to have the power of bending forward and backward, as in the act of nodding, ftooping, looking upward or downward; and, at the fame time, of turning itfelf round upon the body to a certain extent, the quadrant we will fay, or rather, perhaps, a hundred and twenty degrees of a circle. For thefe two purpofes, two diftinct contrivances are employed. Firft, The head refts immediately upon the uppermoft of the vertebræ, and is united to it by a hinge joint; upon which joint the head plays freely forward and backward, as far either way as is neceffary, or as the ligaments allow: which was the firft thing required.