342 STUDIES, SCIENTIFIC AND SOCIAL 



Those who are termed Neo-Da,rwinians do not yet main- 

 tain that use-inheritance (to use Mr. Ball's convenient 

 term) does not exist, but merely that it has not been proved 

 to exist. Whether it actually occurs — and if it occurs at 

 all, I believe it must occur constantly — can only be proved 

 either by very careful and long-continued experiment, or 

 by the demonstration of some theory of heredity which 

 either necessarily includes or excludes it. But even if it 

 does exist I myself believe that it is altogether unimpor- 

 tant as a factor of evolution, and that we have evidence 

 sufficient to prove that natural selection is not inadequate 

 for want of it. 



When we urge that the effects of use-inheritance, if it 

 exists, ought to be abundantly visible in some such ways 

 as I have suggested in the early portion of this chapter, 

 its advocates reply, that only a small portion of what is 

 acquired by the parent is transmitted to the offspring, and 

 that its effects may, therefore, only become visible after a 

 long series of generations ; but as it is necessarily cumu- 

 lative it must produce a considerable result in the course 

 of ages. All we can say in reply to this is, that it is pure 

 hypothesis, and that if true, it may serve to explain the 

 difficulty of obtaining evidence in its favour, but at the 

 same time it indicates that use-inheritance can be of no 

 value as a factor in evolution. Variation is so large and 

 so constant that any required character can be greatly 

 modified in a very short time, of which Darwin gives many 

 illustrations. The comb of the Spanish cock was made 

 upright, the comb and wattles of the Polish fowl were 

 completely abolished, and the average weight of ducks 

 was raised from four pounds to six pounds in a few years. 

 Our sheep, pigs, and cattle were wonderfully improved, 

 and often completely changed in form between the latter 

 portion of the eighteenth and the first half of the present 

 century, while many of our flowers and fruits have been 

 nearly doubled in size, and greatly improved in form and 

 colour in the same period. But natural selection has a 

 great advantage over artificial selection in the enormous 

 scale on which it works, giving much greater scope for the 

 occurrence of favourable variations in large numbers. 



