THE LOGIC OF DARWINISM 539 



therefore the conditions of survival and the qualities required 

 to secure it but that is all it does. Neither the animals that 

 accept man's yoke nor those that survive in spite of him are 

 withdrawn from the realm of nature or escape her law. Her 

 writ runs in byre and garden as well as in forest and plain. 

 The argument from domestication was not therefore an analogy 

 at all, still less a loose one. Improvements of stock by selective 

 breeding constituted in themselves the proof of the theory of 

 selection by demonstrating both the variability of species and 

 the fact that favourable variations do occur and are selected 

 and by accumulation may result in great modifications of any 

 part or character. 



Not only so but in the phenomena of domestication it appears 

 to me we have the only possible complete experimental proof 

 of the theory, which therefore either has been or never can be 

 experimentally proved. That control of organic beings which 

 is requisite in order to constitute an experiment in the 

 phenomena of reproduction can only be obtained by what 

 amounts to domestication. The relation between observation 

 and experiment is similar to that between nature and art, so 

 that the element of art or artifice in domestication, far from 

 vitiating its results as a source of inference, is precisely what 

 makes them the proper material for final and conclusive proof. 



In a word, man being a part of Nature, selection by man 

 does not merely prove but is natural selection and we have 

 11 seen natural selection at work." Nature acting by man's own 

 hand long ago began and has since in an ever-increasing degree 

 continued to select for survival those plants and animals which 

 are useful or pleasing to her simian pet and to destroy his 

 enemies. 



Let us now turn to some fresher expression of opinion on 

 the subject than that above selected. "The theory " (of natural 

 selection), say Profs. Geddes and Thomson in their recent 

 popular hand-book on Evolution, "works well as an inter- 

 pretation but what we need is actual proof of discriminate 

 selection, actual evidence that survivors do survive in virtue of 

 particular qualities." Do not many cows survive in virtue of the 

 particular quality of giving a good supply of milk and many go 

 to the butcher by reason of their failure to do so ; have we 

 not here actual proof of discriminate selection ? As partly 

 satisfying their demand, the Professors go on to describe an 



