122 CHARLES R. STOCKARD AND GEORGE N. PAPANICOLAOU 



which has been fully described scarcely warrants discussion, yet 

 we should like to state in the beginning for the benefit of the 

 casual critic who may not wander through the following pages 

 the real nature of the original control. 



A group of forty animals, eleven males and twenty-nine fe- 

 males, was obtained from a reliable breeder in the early fal of 

 1910. These animals were all under one year old and strong and 

 vigorous in appearance; most of the females were pregnant. 

 All the females were kept until they had produced a normal 

 litter of young. Their production was what would ordinarily be 

 obtained from healthy guinea-pigs; all of the young were nor- 

 mal in appearance and about 80 per cent of them survived under 

 the by no means perfect system of care then employed. 



Three males and six females, after the test matings, were then 

 taken for alcohol treatment. The choice was entirely random, 

 there being no evident marks of superiority or inferiority in any 

 of them as compared with the other animals retained as normal 

 control. One of the three males selected for treatment lived to 

 be more than seven years old, and the others were all healthy, 

 strong animals that lived long and bred vigorously. These 

 treated males were mated with alcoholic females and with nor- 

 mal females. The same normal females were mated at different 

 times with normal males and such offspring were considered 

 control. From the beginning of the experiments it may be said 

 that the same normal female often serves as part of the experi- 

 ment, being mated to alcoholic males and again as the control. 

 The same is true of normal males; they are frequently mated 

 successively with alcoholic females and normal females. From 

 this original stock the normal animals, both males and females, 

 have invariably given rise to average normal offspring when 

 paired with normal mates, while, on the other hand, the treated 

 animals being part of the same breed, have in the quality of their 

 offspring shown a decidedly inferior condition even when paired 

 with normal mates. 



After the experiment had been in progress for eighteen months, 

 in March, 1912, a new stock of animals of an entirely different 

 source from the first lot was introduced. Again, after testing 



