THE BIO GENE TIC LAW 42 5; 



genera, giving the basis of a natural, or biogenetic, classification' 

 of this extinct group. 



Many more cases might be added to those cited here, but 

 surely no additional evidence is needed, for all this points in 

 the same direction, whether gathered by believers in or oppo- 

 nents of the theory of evolution. To this latter class belong the 

 evidence brought forward by Barrande in the ontogeny of trilo- 

 bites, and by Agassiz in the law of recapitulation or acceleration 

 of development. Each of these naturalists used unhesitatingly 

 the method that in the hands of Hyatt and his followers has 

 been so fruitful of results. 



Tames Perrin Smith. 



