DARWINISM ATTACKED. 121 



to the female, and in which sexual selection might be pre- 

 sumed to have been the influence in producing a pronounced 

 male type of preferred pattern, it is this 



Mayer's ex- ^ 



periments on species. Mayer s simple and convincing ex- 

 Promethea, periments were as follows : Mayer took four 

 hundred and forty-nine pupae (in cocoons) of the moth 

 Callosamia promethca, which had been collected in Massa- 

 chusetts and New Jersey, south to Loggerhead Key in the 

 Dry Tortugas Islands off Florida. This island is separated 

 by many miles of ocean from other land, and is hundreds 

 of miles south of the range of the species. Evidently no 

 interference with Mayer's experiments could come from 

 outside individuals of this species. The moths issued during 

 May and June in the proportion of about two males for 

 each female. The males of this species seek out the female 

 for pairing and can do this for a considerable distance. As 

 many as several dozen males will find a single female and 

 hover, fluttering, about her. Mayer's first experiments were 

 directed to the end of determining if the males found the 

 females by sight or by smell. By enclosing females in 

 numerous jars variously arranged and covered or uncovered, 

 it was readily determinable that males never pay any 

 attention to females enclosed in transparent jars so closed 

 as to prevent the escape of any odours from the female, 

 while to females enclosed in boxes or wrapped in cotton so 

 as to be invisible but yet capable of giving odour off into 

 the air males came promptly and hovered about. To locate 

 the organs of scent in the female Mayer cut off abdomens 

 from various females and then placed abdomens and ab- 

 domenless females at some little distance apart. Males 

 came to the abdomens and not to the thorax plus wings, 

 legs, and head parts. Females were proved to increase in 

 attractive power with age, and virgins are a little, but only 

 a little, more attractive than already fertilised females. It 

 was readily proved, by experiments with males whose an- 



