Rau — Longevity in Saturniid Moths. 13 



followed with a like mean of 8.43 days and the Fall River 

 lot brought the lowest mean of 7.63 days. 



This divergence invites investigation. Does the cli- 

 mate under which the larva lives, or the food supply, or 

 the shorter or longer period in the larval stage (due to 

 approaching cold or diminishing food supply), do any 

 or all of these things affect the adult life ? All of the an- 

 imals had fed in their native haunts; all had passed 

 through the entire formative period of their lives under 

 unrestricted, natural conditions of their own habitat; 

 when they came to us they were in the quiescent stage, 

 waiting for the warm days of spring to emerge; nour- 

 ishment could no longer be a factor in their lives. If the 

 St. Louis climate affected the strangers in so marked a 

 degree, why were not all affected alike ? 



This points to new fields of investigation. Herein lies 

 excellent opportunity for ascertaining the causes of 

 lengthened or shortened adult life; whether it be a spe- 

 cific trait or in how far it is merely the result of individ- 

 ual environment; and, if a specific character, whether 

 it can be made to vary as such or can be permanently 

 altered for the race by artificial conditions. It would be 

 well if such work could be done from year to year, at 

 localities remote from one another, individual records 

 in large numbers accumulated, the place mode found and 

 these compared with the climatic and other conditions, 



CALLOSAMIA PROMETHEA. 



In 1911 we obtained notes on the longevity of 170 in- 

 sects of this species from the Creve Coeur region, St. 

 Louis. Here we found that the unmated males lived 

 longer than the mated males, and likewise the unmated 

 females exceeded the mated females, and that the fe- 

 males, all taken together as a class, lived longer than the 

 males. 



In a lot of cocoons of this species received from Fall 

 River in 1913, 104 insects emerged between May 19 and 



