BOOK Jll. C II A P. I. 2S7 



may be very plainl) traced, and of which the degradations are miich 

 flower than thole of fhapc, fii^ure, and other ex.ternal appearances. 

 For, befides the organs of digefl:ion, circulation, and generation, be- 

 longing to all animals, and without which the animal muft ceafe to 

 be an animal, as it could neither fubfift, nor propagate its fpecies ; 

 there Is, e\cn in the parts which principally contribute to the variety 

 of exterior forms, a prodigious refemblance, which ncceflarily reminds- 

 us of an original model, after which every thing feems to have 

 been worked. The body of a horfe, for inftance, which, at firfl: 

 fight, feems fo different from that of a man, when properly compared 

 part by part, inflead of furprizlng us by the difference, fills us with 

 aftonifhment at the lingular and almoft: complete refemblance we find 

 between them ; for, take the Ikeleton of a man, incline the bones of 

 the pelvis, fliorten the bones of the thighs, legs, and arms, lengthen 

 thofe of the feet and hands, conned the phalanges, extend the jaws^ 

 fhorten the frontal bone, and, Inflly, lengthen the fpine ; this Ikeletcn, 

 inftead of refembling any longer the remains of a man, will be the Ike- 

 kton of a horfe. It may be eafily fuppofed, that, by lengthening the 

 fpine and the jaws, the number of the vertebrae, the ribs ar.d teeth are 

 increafed at the fame time ; and it is only in the number of thefe boneSy 

 which may be confidercd as neceflary, and the protrading, lliorten- 

 ing, or junflion of the others, that the Ikeletcn of the body of this 

 snimal differs from that of the human body. But, to carry thefe re- 

 femblances flill further, let us feparately confider fome parts effential 

 to the figure ; the ribs, for inftance, which will be found in man, in 

 all the quadrupeds, in birds, fiflies, and even the veftiges of them, 

 may be traced to the very tortoife, where a delineation of them plainly 

 vrppears in the futures under the fliell. Let italfo be confidcred, that 

 the foot of a horfe,, though in appearance lb different from the hand of 

 a man, is yet compofed of flmilar bones ; and that, at the extremitv 

 of each of our fingers, there is the fame horfe-lhoe fliaped liitle bone, 

 which terminates the foot of that animal ; let It then be decided, whe- 

 ther this latent refemblance be not more aftonifliing than the vilible 

 dltferences ; whether this conftant conformity, and continuing model, 

 followed from man to quadrupeds ; from quadrupeds to the cetaceous 

 fpecies-; from them to birds; from birds to reptiles; from reptiles to 

 fillr, G?c. in which are always found the eflential parts, as the heart, 

 2 intcfline:s. 



