14 Trans. Acad. Sci. of St. Louis. 
June 17, all of which were used in this investigation. 
(See Table 8.) 
The table shows that they were extremely reticent 
about mating in confinement. All our efforts to offer the 
best opportunities brought successful results in the case 
of only four females, and even these rejected the males 
of their own species and mated with Cynthias. This 
table also shows that the unmated females were much 
longer lived than the males and also than the mated fe- 
males, just as they were in the 1911 material, but as a 
whole the duration of life was much greater in the 1913 
Fall River material than in the 1911 Créve Coeur lot. 
Comparing in greater detail these two lots from differ- 
ent localities and years, we find the mean for the males 
to be greater in the former lot by 114 days, and for the 
females by an excess of 2 days. Only consider the mean- 
ing of 2 days in the life of an insect, the duration of 
whose life is from 2 to 12 days. 
It is indeed perplexing when we find that the Poly- 
phemus from Massachusetts showed a mean much lower 
than did those from St. Louis, and that the Prometheas 
from there had a mean duration much greater than those 
from this region. 3 
SAMIA CALIFORNICA, 
Out of a large number of cocoons from Sonoma Co., 
California, only 14 insects emerged. Of these, 12 could 
be used for longevity work. (See Table 9;) 
The table shows that they lived from 7 to 12 days, the 
mean for the entire population being 8.75 days. It is 
much regretted that the number available for this study 
is insufficient for the much desired comparisons, although 
it is interesting to note that these few give evidence of 
the same tendencies as the other species thus far consid- 
ered in that the female sex and the unmated condition 
both tended toward longer life. 
