604 



THE AMERICAN NATURALIST 



[Vol. LI 



than in the former is not clear. It may have been due in 

 part to the greater fluctuations of temperature in the 

 laboratory building used here. Whatever the reason, the 

 control mice in these experiments after the first few 

 months occupied themselves in growing fat instead of 

 having young. 



Stockard's results on guinea pigs are directly contrary 

 to these; his alcoholized animals had decidedly fewer 

 young than the control guinea pigs. 



Comparison op the Growth of the Young in the 

 Various Lines 

 In comparing the weights in Table X and Curve I it 

 should be remembered that all of these young were al- 

 coholized except the male alcohol line and of course the 

 controls. 



TABLE X 



The weights of all the lines at birth and for the first 

 two weeks are quite similar. After that variations began. 

 The young of the double alcohol line surpassed all for four 

 and a half weeks, while the young of the female alcohol 

 line fell behind all the others at the beginning of the third 

 week and remained below up to the seventh week and at 

 the eighth week they were next to the highest. The young 

 of the control line, the male alcohol line and the second 

 generation of the alcohol line grew at about the same rate 

 up to the fifth week. At this time the weight of the male 

 alcohol line slightly surpassed all the others; then the 



