18 



PSYCHE. 



[February 1900. 



some time in any place slie seems to 

 impart an odor to tlie locality, for males 

 will continue to come to it for at least 

 two hours after she has left. 



It is interesting to notice that the 

 females increase in attractiveness as 

 they become older. This was repeat- 

 edly demonstrated as follows. Several 

 females all of which were about six 

 hours old were confined in a large cage 

 made of mosquito netting, and which 

 allowed a very free circulation of air 

 through it. The same number of 

 females about thirty hours old were 

 placed in another similar cage about six 

 feet away from the cage containing the 

 younger females. Out of thirty-seven 

 males, thirty-five came exclusively to 

 the cage containing the older females. 

 Of the other two males, one came to 

 the cage holding the younger females 

 and one divided his attention between 

 both cages. When the females are 

 reversed from one cage to the other the 

 males still go to the cage containing the 

 older females. Upon testing females 

 thirty hours old against females fifty- 

 five hours old, it appears that they are 

 about equally attractive. Thus of 

 seven males, three came to the cage 

 holding the thirty hour old females, one 

 divided his attention between both 

 cages, and three came to the fifty-five 

 hour females. It thus appears that 

 females about six hours old are not so 

 attractive as are females one or two 

 days old. 



Virgin females are more attractive 

 than are fertilized females of the same 

 age. When the virgins are confined in 



one cage and an equal number of fertil- 

 ized females are placed in another cage 

 about five feet away from the former, 

 the majority of the males come to the 

 cage holding the virgin females. Thus 

 out of eleven males eight came to the 

 virgin females, two to the fertilized 

 females, and one to both cages. Fer- 

 tilized females are still quite attractive 

 to males, however, and the males will 

 readily mate with them. This was 

 first observed by Miss Caroline G. 

 Soule, in 1894, who had two female 

 promethea moths, each one of which 

 was mated with four males and still they 

 remained attractive to other males. In 

 fact as long as she remains alive and in 

 health the female attracts males to her. 



One of my males mated four times 

 with three females, and three others 

 mated three times each. The males 

 will make frantic eflbrts to mate with a 

 female which is at the time coupling 

 with another male. 



The mide will fly toward the female 

 with normal eagerness even though his 

 entire abdomen be cut oil", and he will 

 still seek the female when his abdomen 

 is cut oft", and the sides of his thorax 

 are covered with impervious glue. It 

 is therefore evident that the spiracles 

 are not the seat of the organs by which 

 the male perceives the female scent. If, 

 however, the antennae of the male be 

 covered with shellac, glue, paraffin, 

 Canada balsam, celloidin, or photo- 

 graphic paste*, he no longer seeks the 



* The photographic paste used in these experiments is 

 sold in the market under the name of Stofford's white 

 paste. Probably any impervious paste would serve as well. 



