The Descent of Man

ed from the eggs and caterpillars a larger proportion
of males than of females.
Besides the more active habits of the males,
their earlier emergence from the cocoon, and in
some cases their frequenting more open stations,
other causes may be assigned for an apparent
or real difference in the proportional
numbers of the sexes of Lepidoptera, when
captured in the imago state, and when reared
from the egg or caterpillar state. I hear from
Professor Canestrini, that it is believed by many
breeders in Italy, that the female caterpillar of
the silk-moth suffers more from the recent disease
than the male; and Dr. Staudinger informs
me that in rearing Lepidoptera more females
die in the cocoon than males. With many
species the female caterpillar is larger than the
male, and a collector would naturally choose
the finest specimens, and thus unintentionally
collect a larger number of females. Three collectors
have told me that this was their practice;