12 THE PJOLOKICAL PROBLEM OF TO-DAY 



that is latent, and perhaps only imaginary. Thus, 

 craftily, they prepare for our craving after causality 

 a slumbrous pillow, in the manner of the philoso- 

 phers who would refer the creation of the world to 

 a supernatural principle. 



But their pillow of sleep is dangerous for 

 biological research ; he who builds such castles in 

 the air easily mistakes his imaginary bricks, invented 

 to explain the complexity, for real stones. He 

 entangles himself in the cobwebs of his own 



o 



thoughts, which seem to him so logical, that finally 

 he trusts the labour of his mind more than Nature 

 herself. 



' Experiment,' says Weismann in The Germ- 

 plasm, ' is not the only way to reach general views, 

 nor is it always the safest means of discrimination, 

 although at first it seems conclusive. . . - 1 It 

 seems to me that in this case we can draw more 

 prudent conclusions from the general facts of in- 

 heritance than from the results of experiments that 

 are neither quite clear nor undubious, although in 

 themselves they are most valuable, and deserve 

 the most careful consideration. If one remembers 

 what was said in my section on the architecture of 

 the germplasm as the basis of the theory of deter- 

 minants, it will be agreed with me that ontogeny 

 must find its explanation in evolution, and not in 

 epigenesis.' 2 



I take up a more epigenetic position, and years 

 ago I attacked evolutionary doctrines in many of 



1 The Germplasm, p. 137. 2 Ibid., p. 138. 



