DARWIN S VARIOUS WORKS. 1 37 



nomena of organic nature, which agree in bearing testimony 

 to the truth of the Theory of Selection. 



Darwin, at first, intentionally did not notice the important 

 conclusion from his Theory of Descent, namely, the descent 

 of the human race from other mammals. It was not till 

 this highly important conclusion had been definitely estab- 

 lished by other naturalists as the necessary sequel of the 

 doctrine of descent, that Darwin himself expressly endorsed 

 it, and thereby completed his S3^stem. This was done in 

 the highly interesting work, "The Descent of Man, and 

 Sexual Selection," which appeared as late as 1871, and has 

 likewise been translated into German by Victor Carus.*^ 



The careful study which Darwin devoted to domestic 

 animals and cultivated plants was of the greatest import- 

 ance in establishing the Theory of Selection. The infinitely 

 varied changes of form which man has produced in these 

 domesticated organisms by artificial selection are of the 

 very highest importance for a right understanding of animal 

 and vegetable forms ; and yet this study has, down to the 

 most recent times, been most grossly neglected by zoologists 

 and botanists. Without entering upon the discussion of the 

 significance to be attached to the idea of species itself, they 

 have filled not only bulky volumes, but whole libraries, 

 with descriptions of individual species, and with most 

 childish controversies as to whether these species are good, 

 or tolerably good, and bad, or tolerably bad. If naturalists 

 instead of spending their time on these useless fancies had 

 duly studied cultivated organisms, and had examined the 

 transmutation of the living forms, instead of the individual 

 dead ones, they would not have been led captive so long by 

 the fetters of Cuvier's dogma. But as cultivated organisms 



