66 THE MAMMALIA. 



that Filhol distinguishes, among the beasts of prey 

 alone, some forty-two species. In this abundance 

 of forms, in the occurrence of these most varied 

 kinds of flesh- and plant-eaters which cannot be 

 imagined without a struggle for existence we can, 

 as it were, quietly watch the gradual, very gradual, 

 process of transformation, the origin of species. The 

 inestimable value of Filhol's researches, like those 

 of Gaudry, is that they could extend over thousands 

 of objects. His investigations are peculiarly valu- 

 able, owing to the fact that three of the most im- 

 portant deposits of France and of Europe (Quercy, 

 Eonzon, and Gerard le Puy the rich outcome of 

 which he was able to work upon), belong to three 

 closely connected geological horizons. And Filhol 

 has compared in a way that scarcely any other 

 palaeontologist has done the changes and advances 

 of the animal world from one of these periods to 

 the other, in their specialisations, and has placed 

 these in the foreground as the general result of his 

 most careful and detailed accounts. 



Another investigator of great enterprise, Wol- 

 demar Kowalewsky, 1 has unfortunately died at 



1 W. Kowalewsky, Sur V Anchitlierium Aurelianense Cuv. 

 (Acad. de St. Petersbourg, 1873) : Osteology of the Hyopotamidts 

 (Philoso. Transact. 1873) ; Versucli einer natiirlichen Classifies,- 



