110 CARNEGIE INSTITUTION OF WASHINGTON. 



offspring of alcoholic parents and alcoholic grandparents; (3) the controls of 

 each set. The alcoholized rats themselves and their controls were also trained 

 in one problem, Watson's maze. All the other rats were given this problem 

 plus Yerkes's trial-and-error problem. 



"Some work has been done, but not sufficient to be conclusive and no 

 generalization is offered at this time. Table I gives a comparison of the 

 abilities of alcoholics and normals to form a habit; it also shows that in the 

 tests of memory and association the rats of unnarcotized parentage are 

 almost uniformly superior to rats of alcoholic parentage. This is given only 

 as a sample of three trained generations of rats. This family of alcoholic 

 strain represents the best and not the poorest trained family of this strain. 

 The alcoholized rats which were the ancestors of the second and third genera- 

 tions received light doses of alcohol for 3 weeks from the time of weaning 

 (28 days) and then were given heavy doses until they were fully narcotized 

 (dead drunk). The dose of the male was 61 days and that of the female was 

 83 days. Data of other experiments, where the parents received a longer 

 period of treatment and where they received a shorter period of alcoholization, 

 have not been sufficiently collated. All the rats of the first and second gener- 

 ation which were started this year were given the heavy dose from the time 

 of weaning." 



"Growth and fertility of the second alcoholized generation — The administering 

 of alcohol has been carried on to the second generation. The growth and 

 fertility of the first-generation alcoholized rats was considered by Dr. Mac- 

 Dowell in last year's report. This report gives data upon the effect of large 

 doses of inhaled alcohol on the growth and fertility of a series of albino rats 

 whose parents received the alcohol treatment from the time of weaning and 

 who themselves have been subjected to the alcohol fumes from the time of 

 weaning. The alcohol was administered daily and the rats were left in the 

 inhalation tanks till they were in a dead stupor or could move only very 

 feebly. Like the rats of first generation, the time required to produce a drunk 

 stupor was from 3 to 5 hours, according to the intensity of the alcohol vapor 

 in the tanks, the age of the individual, and the sex. Females usually became 

 influenced by the fumes of the same intensity quicker than the males. Rats 

 of both sexes became influenced quicker if subjected to the alcohol vapor 

 before their daily ration than after. As a rule they were put in the tanks 

 early in the morning before they had their bread and milk for the day. Rat 

 biscuit was always hanging in their cages. Normal activity was regained 

 in from 3 to 5 hours. 



"In selecting material for this generation rats were used as near alike in 

 weight as possible at the beginning of the experiment; that is, a rat that was 

 to be alcoholized and its control were selected of the same weight and, when 

 this was not possible, as near alike as could be, but in every case possible 

 the heavier rat of the two was selected for the alcoholic treatment. Except 

 for the alcoholic treatment, all the rats were given the same attention as to 

 food, number in a cage (always one pair), and sanitary conditions. Both 

 sets were in similar cages and placed in adjacent rows. 



"Weekly weighings were made of all the rats and individual growth-curves 

 were plotted. From these curves the weights at the ages considered in the 

 first generation were estimated. In making these estimations allowances 

 were made for temporary losses in weight due to food conditions and to 

 temporary minor illness. The controls were susceptible to skin disease much 

 more than the alcoholics. The skin of the latter was sterilized by the alcohol 

 vapor and hence it was not subjected to vermin. In order to reduce vermin 



