42 



Trans. Acad. Sci. of St. Louis. 



are more often on the wing while the heavily ova-laden 

 females remain secluded. In the data here offered, this 

 chance is eliminated since the material was gathered in 

 the cocoon stage, and usually every cocoon seen in the 

 field was taken. 



From 1909 to 1911 we recorded the sex of 1214 Satur- 

 niid moths (Journ. Exp. Zool., Vol. xii, p. 196), 653 males 

 and 561 females, or a proportion of 116 males to 100 fe- 

 males. In the years 1912 and 1913 we made further rec- 

 ords on these moths, and from these data we have con- 

 structed the following table: 



TABLE 25. 

 Proportion of Sexes. 



Year 



Species 



Number 



Males Females 



Proportion 



Males Females 



1913 

 1913 

 1913 

 1912 

 1913 

 1913 

 1913 

 1912 

 1912 

 1913 

 1913 

 1913 

 1913 

 1913 



S. cynthia, N. Y 



S. cynthia, Phila 



C. promethea, Fall River . . . 



S. californica, Cal 



T. polyphemus, St. Louis 



T. polyphemus, Augusta, Ga. 

 T. polyphemus, Fall River . . 



T. polyphemus, N. Y 



S. cecropia, St. L., R. des P.. 

 S. cecropia, St. L. (fluffy) . . . 



S. cecropia, St. Louis 



S. cecropia, South St. Louis. 



S. cecropia, N. Y 



S. cecropia, Fall River, Mass. 



Total 



75 

 165 



54 

 7 



46 

 316 

 101 



24 



46 



44 

 174 

 113 



76 

 5 



1226 



75 



138 



50 



7 



54 



285 



82 



15 



33 



35 



161 



123 



67 



4 



100 

 119 

 108 

 100 



85 

 146 

 123 

 160 

 140 

 126 

 108 



92 

 113 

 125 



100 

 100 

 100 

 100 

 100 

 100 

 100 

 100 

 100 

 100 

 100 

 100 

 100 

 100 



1129 



108 



100 



These records of 2355 insects show the males again 

 slightly in excess, 1226 males to 1129 females. *By com- 

 bining the data for the five years we find the total of 

 3569 insects comprises 1879 males and 1690 females, or 

 111 males to 100 females. We shall not presume to say 

 how much significance may be attributed to the fact that 



