44 Trans. Acad. Sci. of St. Louis. 
stage. The female, having a large mass of ova to pro- 
duce, has perhaps little time or room to lay up as large a 
store of reserve nourishment, and in many cases it may 
be possible that the supply is insufficient to completely 
carry it through the reproductive period, while in the male 
it may be so great as to carry it far beyond. Again, if the 
reserve nutriment be equal in both sexes, the earlier 
death of the female may be due to the expenditure of a 
greater amount of vitality in the efforts of egg laying. 
We have seen that those females, which had a male 
almost in waiting, so to speak, when they hatched, were 
overtaken by death when all the eggs had been deposited; 
we also found that death, after a time, likewise 
overtook those less fortunate females, who mated late in 
life and were cut short in their ovipositing regardless of 
whether the propagation of the species was assured to 
the fullest extent. For just this reason one is apt to 
think that out of 68 cocoons 43 were males so that they 
might be on hand to properly fertilize the females early 
in life and thus insure perfect oviposition. 
Thus we are led to suppose that the greater number of 
males is an adaptation for the good of the species, and 
that perhaps this came about through natural selection. 
But if natural selection produced a greater number of 
males it also endowed them with a longer duration of 
life, which is as useless to the individual as to the species. 
If natural selection is so great a factor in economic- 
ally producing adaptation, would it not have been easier, 
and perhaps better, to prolong the life of the female just 
a few days or perhaps a few hours to insure perfect 
oviposition, than to produce a greater number of males 
and uselessly prolong their lives to insure impregnating 
the females at an early age? Could it not be possible 
that the phenomena here observed are the. incipient 
stages of higher adaptation, or that at this stage of the 
Cecropia moth we have a phylogenetic vestige of the time 
when the long life of the male was of advantage to the 
species? Perhaps before the mouth parts degenerated, 
