SOCIAL TRANSITIONS 255 



adult female; during the following year he will 

 probably transform into a female. 



The relationships which Dr. Coe observed at 

 Woods Hole may be summarized briefly. Some two 

 hundred young males were taken from their normal 

 surroundings and placed in separate containers in 

 the laboratory. Two months later only ii per cent 

 were still functional males; 15 per cent had trans- 

 formed completely into functional females and the 

 other 74 per cent were on their way in that direc- 

 tion. Random collections of snails of similar sizes 

 which had been left alone in their natural associa- 

 tions showed that 85 per cent were still functional 

 males and only 3 per cent had fully changed into 

 females. 



Coe summarizes his work with this and the other 

 Crepidulas as follows: "There is no doubt but that 

 in each of these three species of Crepidula stable 

 environmental conditions tend to prolong the male 

 phase of these individuals that are suitably mated 

 and sedentary." These points are further illustrated 

 in his diagram, a part of which is reproduced in 

 Figure 46. 



There is evidence from the earlier work of other 

 observers, (54, 87) which these recent studies do not 

 entirely replace, that association with a female is 

 important for the full realization of the male con- 



