440 SOME GENERAL PROBLEMS OF DEVELOPMENT 



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Fig. 229. — A famous experiment showing that germ cells are relatively indepen- 

 dent of the body in which they are found. 



The ovaries of a young female guinea pig (.4.) were transplanted into ,i white guinea pig 

 (B) whose ovaries had been removed. This white guinea pig (B) with the "black" ovaries 

 from A was then bred with a white male (C). Since white is recessive, only white offspring 

 would be expected from such a cross between two white guinea pigs (c/. p. 466). Instead 

 of this all the offspring produced were black like D. The results thus conform to the Men- 

 delian expectation in a cross between black (dominant) and white (recessive) individuals 

 as would be the case here if the eggs of the "black" ovary transplanted into B were unmodi- 

 fied by the white body. (After Castle.) 



