86 THE DOCTRINE OF DESCENT. 



he undoubtedly approached the object at which he aimed 

 — the Natural System. He supplied the first reliable in- 

 formation respecting extinct species. With regard to 

 those which had replaced them in subsequent periods, he 

 was not, as is generally supposed, an unqualified partizan 

 of new creations, but he refrained from any fixed opin- 

 ion. " I will not," he says,^' " positively affirm that for 

 the production of the present animals a new creation 

 was required. I merely say they did not live in the 

 same locality, and must have come from elsewhere." 

 Geoffroy Saint Hilaire, on the contrary, does not doubt 

 that the animals now living are descended, by an un- 

 broken succession of generations, from the extinct races 

 of the antediluvian age. 



Cuvier's method involved the danger of introducing 

 dogmatism into natural science, and it is therefore justi- 

 fiable to refer in this place to one of Cuvier's immediate 

 disciples only recently deceased — Louis Agassiz, who in 

 the most rigidly didactic manner adheres to the syste- 

 matic categories, and invests them with fine-sounding 

 definitions as " embodied creative ideas." ^° According 

 to him, species belong to a particular period in the world's 

 history, and bear definite relations to the physical condi- 

 tions predominant at the time, as well as to the contem- 

 poraneous plants and animals. Species are founded on 

 well-defined relations of individuals to one another and 

 the world in which they live, as well as on the proportions 

 and mutual relations of their parts, and on their orna- 

 mentation. 



Individuals, as representatives of species, bear the 

 closest relations to one another; they exhibit definite 

 relations also to the surrounding element, and their ex- 



