50 An Examination of Weismannism. 



hypothesis caused the interruption, must be inherited 

 by progeny exactly as they occurred in the parents. 

 Or, in other words and adopting Weismann's ter- 

 minology, so far as the facts of heredity are concerned, 

 there is no reason why germ-plasm should not 

 frequently have had its hereditary qualities modified 

 by some greater or less degree of commerce with 

 somatic-tissues, and yet never have reproduced in pro- 

 geny the identical acquired characters which caused 

 the modification of germ-plasm in the parents : some 

 other and totally different characters might with equal 

 — or even more — likelihood have been the result., as we 

 shall see more clearly a few pages further on. Why, 

 then, does Weismann so insist upon this continuity of 

 germ-plasm as perpetual '" since the origin of life " ? It 

 appears to me that his only reason for doing so is 

 to provide a basis, not for his theory of heredity, but 

 for his additional theory of evolution. It is of no 

 consequence to the former that germ-plasm should 

 be regarded as thus perpetual, while it is of high 

 importance to the latter that the fundamental postulate 

 of continuity should be supplemented by this further 

 postulate of the continuity as thus perpetual. 



Similarly as regards the postulate of the stability 

 of germ-plasm as absolute. It is enough for all the 

 requirements of Weismann's theory of heredity that 

 the material basis of heredity should present a merely 

 high degree of stability, such as the facts of atavism, 

 degeneration, &c. abundantly prove that it possesses. 

 For his sequent theory of evolution, however, it is 

 necessary to postulate this stability as absolute " since 

 the first origin of sexual reproduction/' Other- 

 wise there would be no foundation for any of the 



