Bau — Longevity in Saturniid Moths. 33 



The two small lots of Lunas, one from St. Louis and 

 the other from Pike Co., Mo., differ widely in the mean 

 number of eggs carried, but the small number of the St. 

 Louis lot may be attributed to the fact that they were 

 bred in confinement, probably with insufficient or im- 

 proper food. 



The material of S. calif omica is insufficient for com- 

 parison, but shows the mean number of ova produced 

 is 266. 



Among the Cynthias the New York 1912 lot shows the 

 highest mean, 374, but this is for only 6 insects and is 

 worth little in a comparative way, but the fact that these 

 prolific females were all that emerged from about 300 

 cocoons shows the survival of the most vigorous, and 

 that the number of ova is in a way a criterion of vigor. 



We feel sure that further gathering of data on these 

 species from the same localities at intervals of a few 

 years, or for successive years, would show some inter- 

 esting results. Cannot one detect the direction in which 

 the changes are leading the species by a study of such 

 important problems as fecundity or longevity from year 

 to year, as well as by elaborate studies on some morpho- 

 logical detail? 



COMPLETENESS OF OVTPOSITIOET. 



We have just discussed the number of eggs carried by 

 these moths. We shall now take up in detail the ques- 

 tion of complete or incomplete oviposition of these 

 masses in relation to the mated or unmated condition of 

 the individual. 



All or a considerable portion of the eggs are deposited 

 during the life of the insect, regardless of whether or not 

 mating occurs. We have ascertained the number of eggs 

 deposited by each female, and found what per cent this 

 is of the total number carried by her. The population 

 was divided into two great classes, the mated and the 

 unmated, and then tabulated according to the per cent 



