1890 ON WEISMANNISM 269 



selection, while ' vestiges ' of class value are long- 

 enduring. The point to be clear about is that the 

 cessation of selection (in my view) entails two conse- 

 quences, which are quite distinct. First, a compara- 

 tively small amount of reduction due to promiscuous 

 variability round an average which, however, will be 

 a continuously sinking average if the cessation is 

 assisted by a reversal of selection ; and second, later 

 on, a failure of the form of heredity itself. 



Touching the first of the two consequences, you 

 say that ' variations below or away from the standard 

 would not be balanced by those above, because the 

 standard was reached by the selection of such an 

 extremely minute fraction of all variations which 

 occurred.' But can variations in the matter of 

 increase or decrease take place in more than two 

 directions, up or down, smaller or larger, better or 

 worse ? (Eead Wallace, ' Darwinism,' pp. 143-4.) 



I write this in view of the lecture you say you are 

 going to give, because I do not know when ' Nature ' 

 will bring out my article. 



March 20, 1890. 



It might perhaps be well for you to read the type- 

 written reply which I have prepared to Wallace's 

 criticism on ' physiological selection.' But this is 

 for you to consider. He has fallen into some errors 

 of great carelessness, not only with regard to my 

 paper, but also to that of Mr. Gulick, whose theory of 

 ' segregate fecundity ' is the same as mine. On this 

 account I am able to upset the whole criticism, and, 

 bottom upwards, to show that it really supports the 

 theory. 



