THE METHOD 75 



processes only in both cases ; the environment, method, 

 and object of selection being different. 



HYBRIDS. It seems that all the supposed species 

 yet produced in domesticity easily cross, and their 

 hybrids are usually fertile. This appears to indicate 

 that they are not pure species. But may not this be the 

 result of the manner of domestic breeding? Man 

 brings together, sexually, species, that very likely in 

 the wild state, would not be attracted to each other, 

 and, as said before, in case of animal breeding, almost 

 universally man breeds for his own benefit, not for the 

 animal's. This, however, does not solve the problem 

 of sterility, in some hybrids, nor the abstract question 

 of sterility. In case of the mule it has been stated 

 that the impotence is caused by the rudimentary char- 

 acter of the sexual organs. 



Natural selection, then, is the preservation of the 

 favorable individual, hereditary differences and varia- 

 tions. ' ' An individual is said to possess variation when 

 it shows a character not present in its ancestor." 

 (Montgomery, 1906). Variation shows in from ten to 

 twenty per cent of all organic forms. Variations, 

 neither useful nor injurious, would not be affected by 

 natural selection, except to keep them in the adopted 

 form, when they are perpetuated by heredity. 



Says Huxley: "In my earliest criticisms of the 

 'Origin,' I ventured to point out that its logical 

 foundation was insecure, so long as experiments in 

 selective breeding had not produced varieties, that 

 were more, or less, infertile." He means that the 

 domestic breeds would cross, which seems to show 

 that they are not real species, while real natural 

 species would not. But nevertheless, it is a fact, that 

 artificial selection in domesticity has produced, under 



