380 C. L. TURNER. 



previously described specimen there is no duct attached to the 

 aberrant oviducal opening. 



DISCUSSION. 



Since all the specimens taken previously which bore secondary 

 sexual characters of both sexes in the same individual have been 

 females or hermaphrodites the impression might easily arise that 

 some mechanism exists which is capable of producing male 

 secondary sexual characters in females but that either the same 

 or some other mechanism prohibits the reciprocal production of 

 female characters in males. Indeed, the following statement 

 with this implication is made by Hay in a discussion upon 

 " Hermaphroditism in Crayfishes." 1 "It would appear, there- 

 fore, that in the genus Cambarus at least hermaphroditic individ- 

 uals are females which, owing to some ambiguity of the formative 

 cells in the embryo, have developed to a greater or less degree 

 characters of the opposite sex." The finding of only two males 

 having each a single female character furnishes extremely meager 

 data upon which to generalize but it seems important to demon- 

 strate that crayfishes having secondary sexual characters of both 

 sexes may sometimes be males and that no influence exists in the 

 male which completely inhibits the development of female 

 characters. 



1 Smithsonian Miscellaneous Collections. Sept. 8, 1905. 



