WORK IN PALEONTOLOGY 143 



" Happily comparative anatomy possessed a prin- 

 ciple which, well developed, was capable of overcoming 

 every difficulty ; it was that of the correlation of forms 

 in organic beings, by means of which each kind of 

 organism can with exactitude be recognized by every 

 fragment of each of its parts. — Every organized being," 

 he adds, " forms an entire system, unique and closed, 

 whose organs mutually correspond, and concur in the 

 same definite action by a reciprocal reaction. Hence 

 none of these parts can change without the other being 

 also modified, and consequently each of them, taken 

 separately, indicates and produces (donne) all the 

 others. 



" A claw, a shoulder-blade, a condyle, a leg or arm- 

 bone, or any other bone separately considered, enables 

 us to discover the kind of teeth to which they have 

 belonged ; so also reciprocally we may determine the 

 form of the other bones from the teeth. Thus, com- 

 mencing our investigation by a careful survey of any 

 one bone by itself, a person who is sufficiently master 

 of the laws of organic structure can reconstruct the 

 entire animal. The smallest facet of bone, the smallest 

 apophysis, has a determinate character, relative to the 

 class, the order, the genus, and the species to which it 

 belongs, so that even when one has only the extremity 

 of a well-preserved bone, he can, with careful exami- 

 nation, assisted by analogy and exact comparison, 

 determine all these things as surely as if he had before 

 him the entire animal." 



Cuvier adds that he has enjoyed every kind of ad- 

 vantage for such investigations owing to his fortu- 

 nate situation in the Museum of Natural History, 



separately published in 1830. It does not differ materially from the 

 first edition of the Essay on the Theory of the Earthy translated by 

 Jameson, and republished in New York, with additions by Samuel 

 L. Mitchell, in 1818. 



