Normal Starvation 
Males Females Males Females 
< General 
&.2 Population | 32.3361 + 1.0725 | 30.0453-+ 0.9600 | 9.8273 +0.4304| 8.4351-+0.3638 
boo Short lived 31.4147 © 1.4783 | 29.6227+1.2813| 6.5700+0.4205| 9.3235+0.6161 
f=) | Long lived 30.7086 + 1.4109 | 29.1638 + 1.5437 | 12.0179+0.7506 | 7.3585+0.4188 
General 
S'S) Population | 14.5452+0.4479 | 13.8051+0.4137 | 7.6435-+0.3404| 9.4768 +0.4095 
& ©) Short lived 13.4871 +0.5905 | 12.5720+0.4699 | 7.0453+0.4512| 7.1666+0.4719 
Long lived 14.9557 +0.6469 | 14.5707 +0.7280 | 8.1593 0.5057 | 10.8950 0.6240 
6 3 General | 
4°) Population 4,.8147+0.2175 | 4.1844=0.1817 
+ Short lived 5.30130.3450| 4.2622 + 0.2852 
1 &! Long lived 4.1794-+ 0.2622) 3.9303-+ 0.2244 
 t)| General 
= Population 5.4514+0.2464| 4.5596+0.1981 
S = Short lived 5.8148 + 0.3787 | 4.6039+ 0.3081 
Fo °| Long lived 4.5159 +0.2834| 4.4008 0.2514 
1915] 609 
Lutz, Experiments with Drosophila ampelophila. 
correlated with the direct factors than any of the other characters which 
suggested themselves. Table 1 shows that there is a positive correlation 
between these characters, the length of the first posterior cell in the wing 
and breadth of the wing, and the ability to withstand starvation. In two 
cases, the breadth of the wing in males and the length of the posterior cell 
in females, the correlation is certainly statistically significant. In the other 
two cases it Is barely significant. The difference of the means in those 
which died early and those which lived longer (see Table 2) was great enough 
to make it safe to assert that the larger flies, or at least those with larger 
wings, were better able to withstand starvation than those which were 
smaller. 
' Table 3. Coefficients of Variation. See Table 2. 
Since in at least half of the cases the mean had been altered by natural 
selection the coefficient of variation is a better measure of variability than 
is the standard deviation. ‘Table 3 shows that in the American Museum 
“normal” set of experiments there was no very marked difference in varia- 
bility of embryonic periods associated with differences in length of adult life. 
In the other experiments the males which withstood starvation best were 
