Bau — 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 Peres 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, etc.), 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. 



Oviposition. 



numbeb of eggs cakeied. 



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 



