72 Trans. Acad. Sci. of St. Lous. 
before. In the two lots the proportion of fluffy cocoons 
to compact ones was as follows: 
Year No. Flufty No. Compact Total 
1912-13 2 407 
1913-14 2 285 312 
These figures show that in 1912-13 the baggy cocoons 
occurred in, approximately, the proportion of 1 to 3 
and in the following winter 1 to 10. Our previous work 
showed the proportion for 1910 to be 1 to 4, and for 
1911, 1 to 6. 
The sexes, recorded at the time of the emergence of 
the insects from the fluffy cocoons, were as follows: 
Year Males Females Total Observed 
1912-13 44 35 79 
1913-14 10 14 24 
These notes again show that the fluffy cocoons are 
by no means rare, and that both sexes emerge from 
them. It is however of peculiar interest that not -one 
fluffy cocoon was found in a lot of 300 cocoons from 
South St. Louis or the lot of 200 from New York. 
We shall have to seek further for the factors con- 
trolling this fluffy condition. May it be that it is due 
to the mere fact that some larve are more vigorous than 
others, this greater vigor being due to the amount of 
food consumed, and that this greater vigor plus the 
surplus material in the body may express itself in the 
large weaving capacity? 
DURATION OF PUPAL STAGE IN SAMIA CECROPIA. 
Previously’? we found the pupal period of S. ceropia 
to vary from 312 to 324 days. To this we wish to add 
the following data: 
Sex Spinning Completed Emerged Duration 
fe} July 10, 1913 May 23, 1914 317 days. 
rel July 13, 1913 May 23, 1914 314 days. 
Q July 18, 1913 May 25, 1914 311 days. 
d July 15, 1913 May 27, 1914 316 days. 
Q June 15, 1913 May 23, 1914 342 days. 
19 Psyche. 20: 204, 1913. 
