-* 



* 



FIG. 7. A young, black guinea-pig, about three weeks old. Ovaries taken 

 from an animal like this were transplanted into the albino shown immediately 

 below it. 



FIG. 8. An albino female guinea-pig. Its ovaries were removed and in 

 their place were introduced ovaries from a black guinea-pig, like the one shown 

 in Fig. 7. 



FIG. 9. An albino male guinea-pig, with which was mated the albino shown 

 in Fig. 8. 



