Characters, Hereditary and Acquired. 113 



caused by injury to some particular part of the 

 nervous system, I cannot see that there is any 

 reason to doubt the transmission of a nervous lesion 

 merely on the ground that it is not visibly discernible. 

 Of course there may be other grounds for doubting 

 it ; but I am satisfied that this ground is untenable. 

 Besides, it must be remembered, as regards the 

 particular cases in question, that no one has thus far 

 investigated the histology of the matter by the greatly 

 improved methods which are now at our disposal. 



I have now considered all the criticisms which 

 have been advanced against what may be called 

 the Lamarckian interpretation of Brown-Sequard's 

 results ; and I think it will be seen that they present 

 very little force — even if it can be seen that they 

 present any force at all. But it must be remembered 

 that this is a different thing from saying that the 

 Lamarckian interpretation is the true one. The 

 facts alleged are, without question, highly peculiar; 

 and, on this account alone, Brown-Sequard's inter- 

 pretation of them ought to be deemed provisional. 

 Hence, although as yet they have not encountered 

 any valid criticism from the side of ultra-Darwinian 

 theory, I do not agree with Darwin that, on the sup- 

 position of their truth as facts, they furnish positive 

 proof of the transmission of acquired characters. 

 Rather do I agree with Weismann that further in- 

 vestigation is needed in order to establish such an 

 important conclusion on the basis of so unusual a 

 class of facts. This further investigation, therefore, 

 I have undertaken, and will now state the results. 



Although this work was begun over twenty years 



II. I 



