’ 
70 Trans. Acad. Sci. of St. Louis. 
mate in 1913, we selected a few cages containing a pair 
each and introduced into each one a male Cynthia. In 
four cases out of ten mating occurred, the female 
Promotheas giving preference to the Cynthia males— 
or perhaps yielding to their greater animation—and re- 
mained in copulo 24, 12, 10 and ? hours respectively. 
The eggs from these four matings were cared for, but 
all proved infertile. 
June 8 a male Cecropia mated with a female Cali- 
fornica for 10 hours, but the eggs from this crossing 
also were infertile. 
EATING OF EGG SHELLS BY T. POLYPHEMUS. 
We found that when the Polyphemus larve remained 
prisoners in the vials in which they had hatehed from 
the egg, they ate parts of many of the egg-shells. We 
do not know whether it is customary for Polyphemus 
to eat the shell after having emerged from it, or whether 
this is done only in the event of scarcity of other food. 
This practice was not indulged in by the Cynthias, 
Cecropias or Californicas. 
CALLOSAMIA PROMETHEA, 
While the Promethea experiments were in progress 
in 1911, almost every day at about 4 p. m. many free 
males were attracted to the laboratory by the females, 
and when they were placed inside the cages they lost 
very little time before mating. Unlike the Cecropia 
moth which mates just before dawn, the Promethea is in 
copulo before sunset, and while the Crecopia remains in 
mating on an average about 21 hours, this near relative 
continues for only 4 or 5 hours. The duration of copula- 
tion of the 18 pairs was as follows: 
Hours in copulo No. of pairs 
ees than 1 hour's. cc) ago 2 
OS 2 Boater 2 
a Ue noite Se 0 
ote See i 4 
A. 5 eee ee 9 
W000 We oe es 1 
