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THE AMERICAN NATURALIST [Vol. LIII 



other (Ic, 2:58). ^ ' 



The matter of sex-linked characters did not escape Dar- 

 win's observation, alluding to cases where a son does not 

 inherit a character directly from his father, or transmit it 

 directly to his son, but receives it by transmission from a 

 mother who does not show it, and transmits it through his 

 non-affected daughter. Darwin observes : 



We thus learn that transmission and development are distinct powers 

 {ibid.). 



Eespecting the matter of reversion, or what we should 

 now call recombination after segregation, Darwin's utter- 

 ances are remarkable, especially in "Animals and Plants 

 under Domestication." In most cases he regards "re- 

 version" as the coming to light of a "latent" character, 



hornless breeds of cattle possess a latent capacity to reproduce horns, 

 yet when crossed with horned breeds they do not invariably produce 

 offspring bearing horns (Ic, 2:44). 



Darwin deserves credit for strictly contesting the point 

 of view then widely current, that the longer a character is 

 handed down by a breed, the more fully it will be con- 

 tinued in transmission. Discussing some of the cases, he 

 says (Ic, 2:37): 



