308 GEOEGE JOHN EOMANES 1893 



Spencer.' In fact, I have somewhat elaborately 

 sought to prove this in my ' Contemporary Eeview ' 

 article for April, and have been in private correspon- 

 dence with him ever since, but without getting any 

 'forerder,' 



But in this connection I should like to know 

 whether you have any opinion upon the apparently 

 analogous class of phenomena in plants which Darwin 

 gives in the eleventh chapter of his ' Yariation,' &c. 

 Here, it seems to me, the evidence is much more 

 cogent and of far more importance to the issue, 

 Weismann v. Lamarck. Pocke and Dr. Vris, however, 

 seem to doubt the facts or their interpretation, 

 although, as it seems to me, without presenting any 

 adequate reasons for doing so. You need not bother 

 with Dr. Yris, as he merely follows Focke, but I wish 

 you would read Focke ('Die Pflanzen-Mischlinge,' 

 p. 510, et sq.), and compare what he says with the 

 evidence which Darwin presents. 



As I do not know in what respects you have 

 found one part of my previous letter not to ' tally ' 

 with another, I cannot fully explain it ; but I fancy 

 that you will find they do, if, in reading the letter, 

 you carry in your mind the simple proposition that, 

 from the nature of the case, there can be no physio- 

 logical selection except where differentiating varieties 

 (' incipient species ' ) occur upon common areas and 

 identical stations. I do not see any difficulty 

 about willows, roses, brambles, &c., since Naudin's 

 researches on Datura have shown how much vari- 

 ability, due to the hybridisation of any two species, 

 may give rise to the appearance of there being many 



