12 Darwin, and after Darwin. 



of organic evolution several of which, indeed, he 

 himself supplied. Hence we arrive at this curious 

 state of matters. Those biologists who of late years 

 have been led by Weisinann to adopt the opinions of 

 Wallace, represent as anti-Darwinian the opinions of 

 other biologists who still adhere to the unadulterated 

 doctrines of Darwin. Weismann's Essays on Heredity 

 (which argue that natural selection is the only pos- 

 sible cause of adaptive modification) and Wallace's 

 work on Darwinism (which in all the respects 

 where any charge of " heresy " is concerned directly 

 contradicts the doctrine of Darwin) these are the 

 writings which are now habitually represented by the 

 Neo-Darwinians as setting forth the views of 

 Darwin in their -'pure" form. The result is that, 

 both in conversation and in the press, we habitually 

 meet with complete inversions of the truth, which 

 show the state of confusion into which a very simple 

 matter has been wrought by the eagerness of certain 

 naturalists to identify the views of Darwin with those 

 of Wallace and Weismann. But we may easily 

 escape this confusion, if we remember that wherever 

 in the writings of these naturalists there occur such 

 phrases as "pure Darwinism" we are to understand 

 pure Wallaceism, or the pure theory of natural 

 selection to the exclusion of any supplementary 

 theory. Therefore it is that for the sake of clearness 

 I coined, several years ago, the terms " Neo- Darwin- 

 ian " and " Ultra- Darwinian " whereby to designate 

 the school in question. 



So much, then, for the Darwinism of Darwin, as 

 contrasted with the Darwinism of Wallace, or, what 



