ALCOHOLISM AND BEHAVIOR OF WHITE RATS 213 



3) since there are approximately equal numbers of tests and con- 

 trols in this strain the comparative result is left unchanged. 

 The term 'test' is used for a rat receiving alcohol and for its 

 descendants. In the present paper it will refer to the grand- 

 children of alcoholized rats. 



h. Alcoholization of the grandparents 



When the rats to be alcoholized were four weeks old they were 

 weaned; half the litter was saved as control and the other half 

 started with the alcohol treatment. This division of the litter 

 was made purely at random, obviously with no knowledge of 

 the animals' behavior tendencies. Differences in weight at this 

 age are very small and do not bear a very high correlation with 

 adult size. Only litters with at least an even number of males 

 and females could be used; odd individuals were held as stock. 



The treatment was started by placing the rats in tanks of 

 alcohol vapor for thirty minutes a day. After a week of this, 

 the rats were left in the tanks until they were obviously influ- 

 enced by the alcohol; that is, until they showed some lack of 

 control of motion. This would require from one to two hours. 

 This treatment was given for a week. Then they were left in 

 the tanks until they were dead drunk and lay limp ; this took from 

 two to three hours for the young rats and from three to four 

 hours for the old ones. The females received this treatment 

 each day, even through the period of gestation up to a day or 

 two before the birth of the litter, and it was resumed after the 

 young were weaned at twenty-eight days; for the males the 

 treatment was given every day. 'In this way the effective dosage 

 of the two parents was different and it increased for successive 

 litters. The dosage affecting each of the test rats is indicated 

 in the pedigree chart. The numbers in parenthesis after each 

 grandparent represent their respective doses, that of the male, 

 the number of days before conception, and of the female, the 

 number of days up to the day of the birth of the litter. 



As far as possible, the treatment of the rats in the first genera- 

 tion was uniform, with the exception of the alcoholization. The 



