Preface. vii 



will furnish me with the best opportunity of dealing 

 with whatever he may have to say. 



It must be understood, however, that under the 

 term " Weismannism " I do not include any reference 

 to the important question with which the name of 

 Weismann has been mainly associated — i.e., the 

 inheritance or non-inheritance of acquired characters. 

 This is a question of fact, which stands to be an- 

 swered by the inductive methods of observation and 

 experiment : not by the deductive methods of general 

 reasoning. Of course Professor Weismann is fully 

 entitled to assume a negative answer as a basis 

 whereon to construct his theory of the continuity of 

 germ-plasm ; but no amount of speculation as to what 

 the mechanism of heredity is likely to be if once this 

 assumption is granted, can even so much as tend to 

 prove that the assumption itself is true. Therefore, 

 in this "examination of Weismannism" I intend to 

 restrict our attention to the elaborate system of 

 theories which Weismann has reared upon his funda- 

 mental postulate of the non-inheritance of acquired 

 characters, reserving for my next volume our con- 

 sideration of this postulate itself. 



Lest, however, it should be felt that " an examina- 

 tion of Weismannism " in which the question of the 

 transmission of acquired characters is omitted must 

 indeed prove a case of Hamlet without the Prince of 

 Denmark, I may be allowed to make two observations. 

 In the first place, this great question of fact is clearly 

 quite distinct from that of any theories which may be 



