INFLUENCE OF ENVIRONMENT ON SEX 



231 



TABLE 3— Continued 



a colony containing individuals larger than themselves (e.g. 

 large females). 



the 



Experiment 4- Carried on in float-cars, Woods Hole, June to August, 

 1915. The writer collected as many hermit shells as possible where 

 there were no female Crepidulas but only a few small specimens in 

 each hermit shell, all about of the same size. The majority of these 

 had thin, flat smooth shells. They were examined with a lens and the 

 few which showed any development of accessory male organs were 

 discarded. The rest were divided into two lots. Those of one lot 

 (table 5) were allowed to attach themselves inside hermit shells where 

 one or several large females were already attached. Those of the 

 other lot were returned, several together, to hermit shells where there 

 were no other Crepidulas whatever (table 6). It was subsequently 

 found that the sexual condition of an individual is somewhat influenced 

 by the presence of another of only slightly larger size; the experiment 



