46 TABOO AND GENETICS 



uterus and tube into the male body, where it 

 developed normally. One of the most interest- 

 ing of his results is the observation of how the 

 instincts were changed along with the type of 

 body. The feminized males behaved like normal 

 females toward the other males and toward 

 females. Likewise they were treated as normal 

 females by the males. 



It would be impossible to give here any just 

 idea of the vast amount of rigid scientific experi- 

 mentation which has been carried on in this 

 field, or the certainty of many of the results. 

 Sex is really known, about as well as anything 

 can be known, to arise from the chemical causes 

 discussed above. That is, the endocrine ex- 

 planation is the correct one. 



One of the most significant results of the 

 transplantation experiments is the evidence 

 that each individual carries the fundamental 

 bases for both sexes. When Goodale changed a 

 male bird into a female as to secondary charac- 

 ters and instincts by replacing one secretion 

 with another, he was faced with the following 

 problem : How can a single secretion be respon- 

 sible for innumerable changes as to feather 

 length, form and colouring, as to spurs, comb 

 and almost an endless array of other details ? 

 To suppose that a secretion could be so com- 

 plicated in its action as to determine each one 

 of a thousand different items of structure, colour 



