RECAPITULATION 235 



influence of somatic hormones might be made 

 evident. One of these is to graft ovaries or testes 

 from one animal into another which possesses a 

 certain somatic character, and then to see if the 

 offspring produced from these gonads shows any 

 trace of the character of the foreign soma in which it 

 was nourished. C. C. Guthrie ^ claimed to have done 

 this in his experiments on hens. He grafted the 

 ovaries of two Black Leghorn pullets into two White 

 pullets of the same breed, and vice versa. The 

 black and the white birds bred true when mated 

 to cocks of their own colour. The black hen with 

 white ovary mated with black cock produced four 

 black chicks and two black chicks with white legs, 

 the white hen with black ovary mated with white 

 cock produced some white chicks, some black and 

 some white with black spots. This is held to prove 

 that the transplanted ovaries were functional, 

 because they produced evidence of the character 

 originally belonging to them. On the other hand, 

 the black hen with white ovary mated with white 

 cock produced nine white chicks, and eleven chicks 

 which were white spotted with black, and the white 

 hen with black ovary mated with black cock pro- 

 duced not black chicks but white chicks spotted 

 with black. This was held to prove that the 

 somatic characters of the ' foster mothers ' were 

 transmitted. 



Davenport repeated Guthrie's experiments on 

 different fowls, grafting the ovary from a cinnamon- 

 coloured hen into a white hen, and mating her with 

 a cinnamon-coloured cock. The chicks were exactly 

 similar to those obtained from crossing such a cock 



^ Journ. Exper. Zooi. (i'JUS), v. 



