WORK IN PALZAONTOLOGY 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 Zssay on the Theory of the Earth, translated by 
Jameson, and republished in New York, with additions by Samuel 
L. Mitchell, in 1818. 
