i.l RESULT OF THE DISCUSSION 85 



cision because it contemplates no practical application. 

 Let us therefore indicate in a word or two the positive 

 contribution that each of the three present forms of evo- 

 lutionism seems to us to make toward the solution of the 

 problem, what each of them leaves out, and on what point 

 this threefold effort should, in our opinion, converge in 

 order to obtain a more comprehensive, although thereby 

 of necessity a less definite, idea of the evolutionary process. 

 The neo-Darwinians are probably right, we believe, 

 when they teach that the essential causes of variation 

 are the differences inherent in the germ borne by the 

 individual, and not the experiences or behavior of the 

 individual in the course of his career. Where we fail to 

 follow these biologists, is in regarding the differences 

 inherent in the germ as purely accidental and individual. 

 We cannot help believing that these differences are the 

 development of an impulsion which passes from germ to 

 germ across the individuals, that they are therefore not 

 pure accidents, and that they might well appear at the 

 same time, in the same form, in all the representatives of 

 the same species, or at least in a certain number of them. 

 Already, in fact, the theory of mutations is modifying Dar- 

 winism profoundly on this point. It asserts that at a 

 given moment, after a long period, the entire species is 

 beset with a tendency to change. The tendency to change, 

 therefore, is not accidental. True, the change itself would 

 be accidental, since the mutation works, according to 

 De Vries, in different directions in the different representa- 

 tives of the species. But, first we must see if the theory 

 is confirmed by many other vegetable species (De Vries 

 has verified it only by the Oenothera Lamarckiana) ,» and 

 1 Some analogous facta, however, have been noted, all in the vegetable 

 world. See Blaringhem, "La Notion d'espece et la thebrie de la mu- 

 tation" {Annie psychologique, vol. xii., 1906, pp. 95 ff.), and De Vries, 

 Species and Varieties, p. 655. 



