132 An Examination of Weismannism. 



more precise, detailed, and logically coherent structure 

 than any which has ever been framed in this depart- 

 ment of biological thought, there is all the more reason 

 to scan critically the fundamental postulate on which 

 it rests. Hence I cannot help feeling that it will be 

 time enough to consider minor differences between 

 the two theories when the physiological possibility of 

 the occasional transmission of acquired characters, as 

 entertained by Galton's theory, shall have been ruled 

 out as demonstrably opposed to fact. 



Seeing, however, that Professor Weismann thinks 

 otherwise, and appears to attach as much importance 

 to differences concerning deductive minutiae as he 

 does to those concerning fundamental principles, 

 I will here contrast the two theories somewhat more 

 in detail than heretofore, and with special refer- 

 ence to what he has now himself said touching their 

 relationship. 



It will be remembered that the primary or funda- 

 mental difference just alluded to is, that while the 

 theory of germ-plasm postulates an absolute continuity, 

 the theory of stirp postulates but a partial con- 

 tinuity, of the substance of heredity. Hence, ac- 

 cording to Weismann's view, we must go back to 

 the unicellular organisms for the origin of this sub- 

 stance in the multicellular ; and we must regard use- 

 inheritance as physiologically impossible. On the 

 other hand, according to Galton's view, there is no 

 necessity for us to do either of these things. The 

 origin of stirp is to be found in the somatic tissues of 

 the multicellular organisms themselves. Nevertheless, 

 this theory differs greatly from pangenesis, in that the 

 former supposes the origin of hereditary substance to 



