THE STANDPOINT OF BIOLOGISTS. 27 



quired characters. They do not deny that to selec- 

 tion is due by far the most obvious racial changes, 

 and that experimentally the most potent factor in 

 the production of a new variety of a plant or animal 

 is selection. They are, however, inclined to believe 

 that along with this, there may be some transmission 

 of acquired character, only discernible after the lapse 

 of many generations. Darwin himself thought that 

 this was the case ; he held that certain racial distinc- 

 tions were due to the action of the environment on 

 the parents and the transmission of the change thus 

 produced upon their offspring. In his great work 

 upon " The Variation of Animals and Plants under 

 Domestication," l he enumerates some of these. 

 They may be divided roughly into two classes : first, 

 instincts and habits ; and, secondly, results of use 

 and disuse. Darwin believed that the trained habits 

 of dogs and horses, the tameness of the rabbit and 

 other domestic animals, were due to the direct and 

 transmitted effects of man's contact. He held that 

 the large size of the leg and small size of the wing 

 of the domestic as compared with the wild duck are 

 gradually acquired and transmitted by use and dis- 

 use. 



But Darwin, as Huxley points out, 2 was inclined 

 to lay less stress upon the transmission of acquired 



1 Chapter xxvii., vol. ii., 1875. 



8 '* Life and Letters," vol. ii., p. 14. 



