Rau — Longevity in Saturniid Moths. 39 



life. Hence, as we have said, the insect would lose lit- 

 tle if the habit of oviposition were fixed at a later age 

 in order to afford more assurance of a chance of ferti- 

 lization, since egg-laying is heaviest just after copulation. 



THE LAPSE OF TIME BETWEEN THE LAST OVIPOSITION AND 



DEATH IN EELATION TO THE NUMBEK OF 



EGGS RETAINED AFTEB DEATH. 



When we consider longevity in its adjustment to egg- 

 laying in order to insure the perpetuation of the species, 

 one is confronted by these problems : 



(a) Is life long enough to allow the female an opportunity to 



complete oviposition? or 



(b) Are the females cut off by death before their eggs are all laid? 



(c) Is oviposition complete and does the female live for any con- 



siderable length of time without eggs to lay, i. e., a use- 

 less life? 



This table embodies the data from 203 insects. The 

 number of eggs retained by each female when overtaken 

 by death, and the number of days it lived between its 

 last egg-laying and death are presented in Table 23. 



The data of table 23 are summarized in Table 24. 



Here we readily see that there is no relation between 

 the eggs retained and the time of death. We see in the 

 "A class" 102 insects, half of all used in these observa- 

 tions, which died retaining eggs despite the fact of hav- 

 ing 1, 2, 3 or even 6 days of life remaining in which to 

 deposit them; 75 of the insects, or 37% of all observed 

 (class B) were cut short in the midst of egg-laying. The 

 remaining 26 insects, 13% of this population, oviposited 

 completely, 11 of which dutifully died and the remainder 

 lived a useless life of from 1 to 3 days after the comple- 

 tion of egg-laying. 



When we see certain females, both fertilized and un- 

 fertilized, dying in the midst of oviposition, and others 



