2 Trans. Acad. Sci. of St. Louis. 



hand which is the primary and which the secondary func- 

 tion, whether the length of life depends upon the rate of 

 increase, or the rate of reproduction depends upon the 

 length of the generations — in other words, whether ap- 

 proaching death incites reproduction, or reproduction 

 causes death. 



We desired to get at the principles of the duration of 

 life from the standpoint of their efficiency for the per- 

 petuation of the species. Hence we made an extensive 

 study of the longevity of Saturniid moths, with a view to 

 ascertaining just what relationship exists between the 

 longevity and environment and the function of reproduc- 

 tion. These pages embody the results gleaned from the 

 records kept of a large number of individuals of several 

 species for a number of seasons, and from several local- 

 ities. 



The data are presented in the following sequence: 2 



Intboduction. 



Longevity. 



philosamia cynthia. 



tet.ka polyphemus. 



cat.tiosamia pbomethea. 



samia califobnica. 



samia cecbopia. 



discussion of longevity. 



longevity undeb conditions of lowebed tempebatube. 



oviposition. 



number of eggs cabbied. 



completeness of oviposition. 



age when fibst eggs webe deposited. 



age at which the gbeatest number of eggs webe deposited. 



lapse of time between last oviposition and death. 



Pbopobtion of Sexes. 



The Pbiobtty of Male Emebgence. 



The Febtility of Satubniid Eggs in Relation to the Mating Pebiod. 

 intboductoby bemaeks. 

 samia cecbopia. 



2Since it is not customary for the Academy to publish a table of con- 

 tents of its articles, we hope that this syllabus may serve the purpose 

 of locating each unit. 



