296 



THE THEORY OF THE GENE 



has not affected the germ-material by first causing de- 

 fects in the embryo, but has affected both the embryo and 

 its germ-cells at the same time. 



Stockard carried out a prolonged series of experiments 

 on the effects of alcohol on guinea pigs. The guinea pigs 

 were treated by placing them in closed tanks over strong 



Fig. 155. 

 Two abnormal young guinea pigs whose ancestors were alcoholics. 



(After Stockard.) 



alcohol. They breathed the air saturated with alcohol, 

 and after a few hours became completely stupefied. The 

 treatment was carried over a long time. Some of the 

 guinea pigs were bred while undergoing treatment, others 

 onlv at the end of the treatment. The results were essen- 

 tially the same. Many young were aborted or absorbed, 

 others were born dead, others showed abnormalities, 

 especially in the nervous system and eyes (Fig. 155). 

 Only those that themselves showed no defects could be 

 bred. From these, abnormal young continued to appear 



