EFFECTS OF DRUGS ON WHITE MICE 149 



and their minimum weekly run is 24 415. Their average total 

 activity is 68 per cent of the controls. 



The caffeine mice, with the exception of No. 14, gained 11.6 

 grams each, which was more than any other line gained. But 

 as they started out the smallest of all the mice and at the end of 

 the experiments equalled the controls in weight, they apparently 

 grew normally. No. 14 gained 3.5 grams and lost it again before 

 its death. 



The growth of three of these mice does not seem to have been 

 affected by caffeine. One, however, seems to have been injured, 

 for it died when thirty-two weeks old. 



Caffeine appears to have decidedly lessened the activity of the 

 mice. 



smiMARY 



1. The control mice gained 7 grams on an average during the 

 experiment. None of them died. Three were above the average 

 in activity. Their total activity was greater than any other line. 



2. The alcohol mice gained 6 grams on an average up to the 

 twenty-fourth week, but lost 4.5 grams later. Two died and one 

 probably would have died soon. Three were below the average 

 in activity. Their total activity was 73 per cent of that of the 

 controls. Alcohol appears to have had a markedly injurious 

 effect on the viability and activity of these mice. 



3. The mice subjected to nicotine gained 2 grams each on an 

 average. None died. Two were below the average in activity 

 and two above, one being far more active than any other mouse in 

 any ot the lines. Their total activity was 99 per cent of the 

 controls. 



Nicotine apparently did not injure the health of the mice, but 

 seems to have checked their growth. 



Nicotine may have had a stimulating effect on the activity of 

 three of the mice. Or it is possible that the variations shown in 

 this line were due to chance. 



4. Three of the mice subjected to caffeine gained 11.6 grams 

 each on an average, but since they started out the smallest of all 



