1890 OX WEISMAXXS THEOEY 2-2o 



structures — e.g. instincts — and also on the ground of 

 his theory of Pangenesis. Therefore I abandoned the 

 matter, and still retain what may thus be now a pre- 

 judice against exactly the same line of thought as 

 Dar\\in talked me out of in 1873. Weismann, of 

 course, has greatly elaborated this Mne of thought ; but 

 what niaj' be called the scientific axis of it (viz. 

 possible non-inheritance of acquii-ed characters) is 

 identical, and all the more metaphysical part of it 

 about the immortahty, immutabihty, <tc., of a hypo- 

 thetical germ-plasm is the weakest part in my esti- 

 mation. 



Xow, the point I am working up to is this. If there 

 be no difierence between Panmixia and Cessation of 

 Selection, from what I have briefly sketched about it, 

 it follows that, had Darwin Kved till now, he would 

 almost certainly have been opposed to Weismann. 

 This is not a thing I should like to say in pubhc, but 

 one that I should like to feel practically assured about 

 in my own mind. 



Regarding the numerical calculations, I have not 

 got a copy of the ' Nature ' paper here, but, so far as I 

 remember (and I think I am right), the idea was that 

 ' Economy of Growth ' would go on assisting Cessa- 

 tion of Selection till the degenerating organ became 

 ' rudimentary.' In other words, reversal of selection 

 would co-operate with cessation of it. 



This, as I understand it, is nowexactlyWeismann's 

 view; only he thinks that thus the rudimentary organ 

 would finally become extinguished. Here, however, 

 it seems to me evident he must be wi-ong. The 

 reasons ai"e obvious, as I am going to show this week 



