EFFECTS OF DRUGS ON WHITE MICE 143 
TABLE 12 
Average of one female of the first generation for seven months 
LINE | AVERAGE NUMBER OF | AVERAGE NUMBER OF PER CENT OF YOUNG 
LITTERS YOUNG | THAT DIED 
Controle santas eon cc ee 2.2 13.3 0 
AIG OH ON Meas tie teh 2.8 16.1 Til al 
INTC OAM. .cce re reas ater 2.8 17.3 17.3 
SLINOLAEC | Soop coro ami cool 4.0 24.6 37.0 
Guiheimen. eo seso ins cee: | Psat 14.1 25.3 
TABLE 13 
Average of one female of the second generation for four months 
LINE AVERAGE NUMBER OF AVERAGE NUMBER OF | PER CENT OF YOUNG 
LITTERS YOUNG THAT DIED 
Controle 4.5. -ose oes 5) tal 0 
INGO Voll, Season wae shee dol 1.8 12.4 12.5 
INT COLIN ere 1.66 10.0 16.6 
Smokedee ee. Aa 2.26 13.4 26.0 
In both generations the mice subjected to tobacco fumes had 
more young than any of the other lines, whereas the controls had 
the fewest young. ‘Tobacco fumes had a marked effect on the 
viability of the young, since 37 per cent of the first generation 
died from lack of vitality and 26 per cent of the second. One 
abortion occurred in this line. Caffeine was also injurious to the 
young, 25 per cent dying. Nicotine and alcohol had a less notice- 
able influence. None of the control young died in either gener- 
ation. 
GROWTH OF THE YOUNG SUBJECTED TO THE SAME CONDITIONS 
AS THEIR PARENTS 
The young were either weighed singly or in litters at birth and 
every week for eight weeks. Since it was not always possible to 
weigh them before they suckled, the variations in the birth weights 
have little significance. The records were not carried beyond 
eight weeks for the young females often become pregnant at that 
time. 
