36 THE GEOLOGICAL EVIDENCES 



before us, as coming from the side of both rap- 

 tile and bird, that the two classes of animals 

 are simply modifications of the same stock, 



Compsognathus longipes. 



and that the one (the bird) is a derivative of 

 the other (reptile). The zoological relationship 

 clearly points to the nature of this derivation, 



