138 L. B. NICE 
The caffeine line 
This line consisted of 6 female and 3 male mice. No second 
generation was obtained for breeding since many of the young 
died and others were eaten by their parents. 
Each mouse had 2 ce. of 1:100 caffeine citrate solution added 
to his crackers and milk daily, and drank this solution instead 
of water. The caffeine citrate was first given in a 1:500 solution 
which was gradually increased to a 1:50 solution. Since they did 
not seem to be thriving on this strength it was decreased to 1:100, 
on which they remained in good health. 
All the mice in this line except 8 received caffeine, the young 
beginning to take it at the age of three weeks. Hight young were 
given no caffeine themselves, although their mothers received it 
for sixteen days after the birth of the young. 
The control line 
The first generation of control mice consisted of 6 females and 
3 males. Since these mice had few young and many were eaten 
there were none of the second generation ready for breeding three 
months after the experiments were started. Therefore 6 young 
females and 3 males were obtained from the same source as the 
first lot of mice so as to serve as controls for comparison with the 
second generations of the other lines. 
EFFECTS ON THE WEIGHT AND HEALTH OF THE ADULT MICE 
The females were weighed each time after they had given birth 
to a litter, and the males from time to time. During the course 
of the experiments all the mice gained in weight; in the first genera- 
tion, carried seven months, the alcohol mice gained 6 grams each on 
an average, and the others gained 2 grams; in the second genera- 
tion carried four months, the aleohol mice gained 2 grams and the 
others 1 gram. This would indicate that the mice remained 
healthy and that alcohol has a fattening effect. 
