THE REPRODUCTIVE FACTOR IN EVOLUTION. 277 



external forces, His keen analysis of possible factors did not fail 

 to recognize — what Brooks, Galton, Weismann, and others have 

 since elaborated — that the union of diverse sexual elements in fertili- 

 zation was in itself a fountain of change. " Every form of life," he 

 says, ' ' may have been produced by physical forces in either of two 

 ways, either from formless matter, or by the continuous modification 

 of form. In the latter case, the cause of change may be either in the 

 influence of the hctrogeneous male reproductive matter on the female 

 germ, or in the influence of other potencies after generation." 



His contemporary Lamarck f writing in 1 801-9) — of greater post- 

 humous fame — fought in poverty like a hero for the evolutionary 

 conceptions of his later years. He is well known to have emphasized 

 the importance of changed conditions in evoking new needs, desires, 

 and activities, urging at the same time the perfection wrought upon 

 organs by increased practice, and conversely the degeneration which 

 follows as the nemesis of disuse. Evolution seemed to him to be 

 due to the interaction of two fates, — an internal progressive power of 

 life; and the external force of circumstances, encountered in the 

 twofold struggle with the inanimate environment and with living 

 competitors. 



3" Among the philosophers, too, and especially in the minds of 

 those who have been disciplined in physical or historical investigations, 

 the speculations of the ancients were ever taking fresh form, gaining 

 moreover in concreteness. Thus Kant viewed the evolution of species 

 mainly in terms of the mechanical laws of the organism itself, but 

 allowed also for the influence of environment, noted the importance 

 ©f selection in artificial breeding, and, like such ancients as Empe- 

 docles and Aris^oJ^Jia^gjimpses of the notion of the struggle for 

 existence. The same idea is more distinct in Herder's " Philosophy of 

 History," where, probably under Goethe's influence, he speaks of the 

 "struggle, each one for itself, as jfit were the only one," of the limits 

 of space, and of the gain to the whole from the competition of individ- 

 %• uals. Oken (1809) saw the light of the evolution idea dancing like a will- 

 o'-the-wisp in the mist of his " Urschleim " speculations, and seemed 

 chieflyToTnterpret the organic progress in terms of action and reac- 

 tion between the organism and its surroundings; while in the noble 

 epic of evolution which we owe to his contemporary Goethe, the 

 adaptive influence of the environment is clearly recognized. 



Wells in 1813, and Patrick Matthew in 1831, forestalled Darwin 

 in suggesting the importance of natural selection; but their virtually 

 buried doctrines, however interesting historically, were of less prac- 

 tical importance than those of Robert Chambers, the long unknown 

 author of the " Vestiges of Creation " (1844-53). His hypothesis of 



