Rau — Observations on Samia Cecropia, Linn. 41 



VI. General Considerations and Conclusions. 



(a) General Considerations. 



Only in a very few instances does Weismann give us 

 any facts as to the duration of life of the male and 

 female of any moth, and in those few instances the spe- 

 cies is allied to the Cecropia moth. Since the moths are 

 somewhat analogous, a comparison of Weismann 's facts 

 with notes upon the Cecropia moth will not be out of 

 order in a paper of this kind. 



In his essay on Life and Death 4 Weismann says: 

 "Lepidoptera, such as the emperor-moths and lappet- 

 moths, lay their eggs one after another and then die. 

 We may certainly say that these insects die of exhaustion; 

 their vital strength is used up in the last effort of laying 

 eggs, and in the case of the males, in the act of copula- 

 tion. Eeproduction is here certainly the most apparent 

 cause of death, but a more remote and deeper cause is 

 to be found in the limitation of vital strength to the 

 length and the necessary duties of the reproductive 

 period. They live in a torpid condition for days or weeks 

 until fertilization is accomplished." 



The emperor-moth as well as the Cecropia moth be- 

 long to the family Saturniidae. Neither species in the 

 imago state takes nourishment, still there seems to be 

 some difference in the duration of life of the emperor- 

 moth when compared with that of the Cecropia moth. 



The female Cecropia moth does not die after egg 

 laying, and the males in the act of copulation, as Weis- 

 mann tells us of the emperor moth; but the female 

 Cecropias die, in the greater number of cases, before 

 all the eggs are deposited, while the males live, on an 

 average of 9 days and 42 minutes, after separating from 

 the females. 



The female Cecropias do not live in a torpid condition 

 for days or weeks until fertilization is accomplished, but 



4 Essays upon Heredity. English translation. 159. 1891. (2d Ed.) 



