190 EVOLUTION 



Treviranus (1776-1837), whom Huxley 

 ranked beside Lamarck, was on the whole 

 like Buffon in attaching chief importance to 

 the influence of a changeful environment, 

 both in modifying and in eliminating. But 

 he had another deep idea, which Goethe 

 shared, of an inherent formative impulse in 

 the creature. " In every living being there 

 exists a capability of an endless variety of 

 form-assumption ; each possesses the power 

 to adapt its organization to the changes of 

 the outer world, and it is this power, put 

 into action by the change of the universe, 

 that has raised the simple zoophytes of the 

 primitive world to continually higher stages 

 of organization, and has introduced a count- 

 less variety of species into animate Nature." 



But it is in Goethe that we find the fullest 

 expression of the idea of the innate tendency 

 of a living creature to fuller self-realization. 

 At the same time he held with Lamarck that 

 " the way of life powerfully reacts upon all 

 form," and with Buffon that the orderly 

 growth of form "yields to change from 

 externally acting causes." 



The main idea of Goethe, of an inherent 

 growth force, has constantly reappeared, 

 notably among the American palaeontologists : 

 witness Cope's " bathmism "; and now among 



