xviii TRANSLATOR'S PREFACE 



The Neo-Darwinians say that it is quite true that such 

 modifications were produced by the functional activity in the 

 individuals, but these modifications were never inherited : 

 other modifications of the same kind arose by congenital 

 variation in some of the same individuals, and the indi- 

 viduals that had these survived ; and then the favoured 

 individuals pairing together, some of their offspring, inherit- 

 ing from both parents, had the modification in a greater 

 degree, and so on. Which is very much like the argument 

 that the Iliad and the Odyssey were not written by Homer, 

 but by another man of the same name who lived at the 

 same time. 



Professor Weismann's view of heredity is not, as he seems 

 to think, in any sense an explanation or an approach to it. 

 We are unable to comprehend how the individual impresses 

 upon the germ the power of growing into another individual 

 like itself, supposing that we regard heredity in this way. 

 But even if it were perfectly certain that heredity had 

 nothing to do with the influence of the " soma," but con- 

 sisted entirely in a fixed tendency of the germ -plasm to 

 develop into a certain type of adult organism, this fixed 

 tendency would be as absolutely unexplained as the influ- 

 ence of the body on the germ-cells on the other hypothesis. 

 Moreover, we have no evidence in support of the assumption 

 of such a fixed tendency. It is a known fact that the 

 development of an individual depends to a very great degree 

 on the conditions under which that development takes 

 place. The very occurrence of the process of development 

 from the ovum to the adult is dependent upon certain con- 

 ditions ; outside a certain minimum and maximum of 

 temperature, food, light, moisture, etc., the e^^ or embryo 



