64 ON THE REVOLUTIONS OF 



formation of the teeth, the shape of the jaws, the structure of the ver- 

 tebrae, and the form of all hones of the legs, thighs, shoulders, and 

 even the frame of the animal which has passed. It is a more certain 

 mark than all those of Zadig. 



Whatever secret reasonings there maybe in these relations, it is ob- 

 servation which has elicited them, independently of general philosophy. 



In fact, when we make an assemblage of these facts, we remark not 

 only a specific consistency, if we may use such a term, between a cer- 

 tain formation of a certain organ, and a certain formation of a different 

 organ ; but we perceive also a classified consistency, and a corres- 

 pondent gradation in the developement of these two organs, which 

 evince, almost as well as an effective reasoning, their mutual influ- 

 ence. 



For example, the dental system of hoofed animals, not ruminant, is 

 usually more perfect than that of cleft-footed animals, or those which 

 ruminate, because the former have either incisors or canine teeth, 

 and generally both in both jaws ; and the structure of their foot is 

 more complicated, because they have more toes, or nails which less 

 enclose the phalanges, or more separate bones of the metacarpus and 

 metatarsus, or the bones of the tarsus more numerous, or a more dis- 

 tinct prominence of the tibia, or in fact, because they unite all these 

 points. It is impossible to account for these correspondences; but 

 what proves that they are not the effect of chance, is, that whenever a 

 cleft-footed animal shows, in the arrangement of its teeth, any tendency 

 to a similarity with the animals of which we are speaking, it also 

 evinces a similar tendency in the formation of its feet. Thus camels, 

 which have canine teeth, and even two or four incisors in the upper 

 jaw, have a bone more in the tarsus, because their scaphoid is not 

 united with the cuboid, and very small nails corresponding with the 

 phalanges which have nails. The chevrotians, whose canine teeth are 

 much developed, bear a distinct mark along the tibia, whilst other 

 cleft-footed animals have only, instead of the fibula articulated, a 

 small bone along the tibia. There is then a constant harmony be- 

 tween two organs apparently very distinct from each other ; and the 

 gradations of their formation correspond without alteration, even in 

 cases where we can assign no cause for the similarity. 



But, in thus adopting the method of observation as an additional 

 means when theory forsakes us, we arrive at astonishing results. The 

 least prominence of the bone — the smallest apophysis — has a deter- 

 mined character relative to the class, the order, the genus, and even 

 the species to which it belongs ; so that whenever we have only the 

 extremity of a well-preserved bone, we may, by scrutinizing it, and ap- 



