Rau—Longevity in Saturmid Moths. 71 
In addition to these, many other pairs were left in 
copulo during the evening, but early the next morning 
they were found to have severed. 
Judging from the short life of the Prometheas, and 
knowing that the Cecropia moths are mostly monogam- 
ous, we might almost assume that this species is also 
monogamous. From a small number of experiments 
this seems to be true, and in the case of all of the 24 
females which mated, the males were allowed subse- 
quently to remain in the cage. In these cases a second 
mating was never observed, although the usual period 
of mating is so short that mating could have occurred 
at a time when constant watching was impossible. 
Some slight interest may be attached to the age of the 
insects when mating began, to see at how early or how 
late an age the moths were capable of mating. 
Age Females Males 
6 hours or less ........--+-+++:- 
1 
6 tO 12 HOUT ie eee es 8 9 
42 to: 18 hours sae eres ss 1 0 
48 46-24 Outre =. 8 see ees 1 0 
4362 - GAVE a re eee 1 cf 
DOS GRVS oi ee es ee y 3 0 
B10 ROAG8 er oe a ae ees 2 1 
Bh Re ie li eee kas ae 0 0 
B60. 6 GAYS iit cee tes eee s 1 0 
This table shows that 21 out of the 30 insects of both 
sexes mated before 24 hours of age. 
FLUFFY CECROPIA COCOONS. 
In 191118 we discussed the nature and abundance of 
the cocoons of Samia cecropia. During the past two 
years we have made additional observations which are 
interesting since they substantiate the earlier ones. 
During the winters of 1912 and 1913 cocoons were gath- 
ered from the River des Péres region, the same area as 
18 Psyche. 18: 168-170, 1911. 
