142 Darwin, and after Darwin. 



(C.) 



Experimental Evidence as to the Non-inheritance 

 of Acquired Characters. 



Let us now proceed to the experimental evidence 

 which has been adduced on the side of Weismannism. 



Taking this evidence in order of date, we have 

 first to mention that on which the school of 

 Weismann has hitherto been satisfied almost ex- 

 clusively to rely. This is the line of negative 

 evidence, or the seeming absence of any experimental 

 demonstration of the inheritance of acquired char- 

 acters. This kind of evidence, however, presents 

 much less cogency than is usually supposed. And 

 it has been shown in the last chapter that the 

 amount of experimental evidence in favour of the 

 transmission of acquired characters is more con- 

 siderable than the school of Weismann seems to be 

 aware especially in the vegetable kingdom. I do 

 not think that this negative line of evidence presents 

 much weight ; and, to show that I am not biassed 

 in forming this judgement, I may here state that few 

 have more reason than myself for appreciating the 

 weight of such evidence. For, as already stated, 

 when first led to doubt the Lamarckian factors, now 

 more than twenty years ago, I undertook a research 

 upon the whole question only a part of which was 

 devoted to testing the particular case of Brown- 

 Sequard's statements, with the result recorded in the 

 preceding chapter. As this research yielded negative 

 results in all its divisions - and, not only in the matter 

 of Brown-Sdquard's statements I have not hitherto 



