Correspondence on Biology, etc. 



couple. The article was in print last September, but, 

 being long, was crowded out month after month, and only 

 now got in by being cut in two. I think I have demolished 

 '' discontinuous variation " as having any but the most 

 subordinate part in evolution of species. 



Congratulations on Presidency of the Entomological 

 Society. A. R. Wallace. 



To Prof. Poulton 



Parkstone, Dorset. March 15, 1895. 



My dear Poulton, — I have now nearly finished reading 

 Eomanes, but do not find it very convincing. There is a 

 large amount of special pleading. On two points only I feel 

 myself hit. My doubt that Darwin really meant that all the 

 individuals of a species could be similarly modified without 

 selection is evidently wrong, as he adduces other quotations 

 which I had overlooked. The other point is, that my sug- 

 gested explanation of sexual ornaments gives away my case 

 as to the utility of all specific characters. It certainly does 

 as it stands, but I now believe, and should have added, that 

 all these ornaments, where they differ from species to species, 

 are also recognition characters, and as such were rendered 

 stable by Natural Selection from their first appearance. 



I rather doubt the view you state, and which Gulick and 

 Romanes make much of, that a portion of a species, separated 

 from the main body, will have a different average of char- 

 acters, unless they are a local race which has already been 

 somewhat selected. The large amount of variation, and the 

 regularity of the curve of variation, whenever about 50 or 

 100 individuals are measured in the same locality, shows 

 that the bulk of a species are similar in amount of variation 

 everywhere. But when a portion of a species begins to be 

 modified in adaptation to new conditions, distinction of 

 some kind is essential, and therefore any slight difference 



