OLFACTORY BULBS OF THE ALBINO RAT pipet 
ative weight, the difference is not so serious a matter as it would 
be were the rats younger. 
The set of test animals killed at the end of one hundred and 
three days of exercise, gave bulbs averaging for the males 4.28 
per cent of the entire brain weight, and 4.60 per cent for the 
females—an average of 4.41 per cent for the entire set (table 19). 
When these results are compared with the controls (table 20) 
we find that while the test animals were 1 per cent shorter than 
the controls and had brains 2 per cent lighter in weight, the 
olfactory bulbs were 3 per cent heavier. These results seem to 
indicate that the olfactory bulbs of the test animals have been 
affected by exercise. 
An examination of the records for the initial controls of the 
litters concerned seems to give additional weight to this supposi- 
tion. See table 23 below. 
‘TABLE 18. SERIES E 
Initial control animals 
Males 
OLFACTORY 
OLFACTORY BULBS: 
ANIMALS sce | werent | umnata | weronr | BOERS | PER cENT 
WEIGHT 
days grams mm. grams grams 
Wi 30 26 99 1.338 0.052 3.89 
Yenils Sees ae teeta 30 36 104 1.254 0.052 4.18 
Wire teet ce cuatiey csthowsnte chs 30 Al 109 1.472 0.056 3.83 
ate ies: St es ops ty | bt 30 41 112 1.444 0.050 3.46 
Tpit os Ste IO A a A 30 46 12 1.452 0.056 3.87 
Average males....... 38 109 1.392 0.053 3.84 
Females 
Vie ee eee a inate ae ah Ree 30 29 96 al 0.043 3.57 
BCs OA ee 30 24 96 1.280 0.045 3.52 
RP occs aiclosnhans 30 28 101 1.338 0.034 2.51 
Wiser oro eka ees 30 34 107 12335 0.043 See 
Wish ae Fe one eels 2 30 43 114 1.432 0.048 3.34 
Average females...... 31 103 1.319 0.043 3.27) 
Average males and 
femalesteeeenes ...- 35 106 1.356 0.048 3.54 
