CLASSIFICATION. 83 



Generalized types. Embryonic types. Prophetic 

 types. Recognized by Agassiz in the geological record. 



Development of vertebrates. 



Evolution and differentiation of fishes. 



Why the "highest fishes first" ? Confusion in the 

 meaning of " highest." 



Derivation of batrachia from fishes. 



Derivation of reptiles, birds, and mammals. 



