Rau—Longevity in Saturnud 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 RELATION TO THE NUMBER OF 
EGGS RETAINED AFTER 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 ghey complete and does the female live for any con- 
e length of time without eggs to lay, 7. €., a use- 
less one 
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, 138% 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 
