Rau—Longevity in Saturniid Moths. 29 
days longer in the basement than did those in the living- 
room, the females 2.70 days longer, and the whole popu- 
lation 3.30 days longer than their more energetic fellows. 
In January and February 69 adult Cecropias emerged 
from cocoons gathered from the River des Péres region 
and kept in a living-room which was slightly heated dur- 
ing the day, but almost always:cool at night. The table 
shows the duration of life of these insects. (See Table 
18.) 
Some lived but a very short time, due perhaps to ab- 
normalities or weakness resulting from their premature 
development and emergence, but for the most part they 
gave results comparable with the ice-box experiments of 
1910 (loc. cit., p. 190), and while the mean duration of 
life is not so great in all of these three lots, yet we found 
the maximum duration of life to be even greater than 
in the ice-box work. 
Since these various conditions of lower temperature 
prolonged the lives of the insects considerably, and since 
the extreme conditions of the ice-box prolonged them ex- 
tremely, one cannot evade the conclusion that tempera- 
ture is a factor which to a great extent controls the 
length of life of these delicate organisms. It may be 
only a matter of delicate, refined technique (slowly and 
gradually lowering the temperature, with proper venti- 
lation, ete.), that is needed to suspend metabolism and 
increase the longevity in these frail creatures to surpris- 
ing extremes, since it seems principally a matter of con- 
servation of energy until it is necessary for such energy 
to be expended. Such phenomena undoubtedly occur in 
the Lepidoptera which hibernate as imagines. 
OviIposITIon. 
NUMBER OF EGGS CARRIED. 
The moths of the family Saturniidae here considered 
hibernate as pupae in silky cocoons. The caterpillars, 
heavy consumers of vegetation, stop feeding at a certain 
