110 BIOLOGY AND SOCIAL PROBLEMS 



on pedigreed guinea-pigs and with results of a 

 more conclusive character. I shall state these 

 in Castle's own words : " A female albino 

 guinea-pig, just attaining sexual maturity, was 

 by an operation deprived of its ovaries, and 

 instead of the removed ovaries there were in- 

 troduced into her body the ovaries of a young 

 black female guinea-pig, not yet sexually ma- 

 ture, aged about three weeks. The grafted 

 animal was now mated with a male albino 

 guinea-pig. From numerous experiments with 

 albino guinea-pigs it may be stated emphatic- 

 ally that normal albinos mated together, with- 

 out exception, produce only albino young, and 

 the presumption is strong, therefore, that had 

 this female not been operated on she would 

 have done the same. She produced, however, 

 by the albino male three litters of young which 

 together consisted of six individuals." " The 

 first litter . . . was produced about six months 

 after the operation, the last one about a year. 

 The transplanted ovarian tissue must have re- 

 mained in its new environment, therefore, from 

 four to ten months before the eggs attained 

 full growth and were discharged, ample time, 

 it would seem, for the influence of the foreign 

 body upon the inheritance to show itself were 



