238 F. E. CHIDESTEK. 



Micce-sive occasions and in r.n-h case tin- female began to move 

 herself into the copulating position by walking around the legs 

 of the male, plating her legs between and against his. In one 

 of these cases, tin- f finale moved so rapidly that the male may 

 have thought ^he was attempting to escape, for he beat upon her 

 carapace in the attempt to quiet her. 



It is extremely in ten- Mini; to see such activity on the part of 

 the female crab, when one has as a contrast the passivity of the 

 female crayfish. 



\Yhen tli^ female crab has turned about two thirds of the way 

 around, adjustment of the abdomens must be made. As above 

 stated, the abdomen of the ovigerous female is not bound by 

 hooks to thi- body and is held flexed by muscular contraction. 

 During the preliminary maneuvers, the abdomen of the female 

 i- Ill-Id slightly extended, and the male mn>t push this partially 

 extended obstacle out still farther and interpose his own telson 

 between it and the body of tin- female. In the case of the blue 

 crabs this is not difficult. The verges of the male are inserted 

 in the seminal receptacles of the female, and copulation takes 

 place. The male carries the female about, grasping her with the 

 tips of his ambulatory appendages, and holding her for hours, 

 sometimes days. \Yhile the act of copulation is going on, the 

 female is exceedingly quiet. The male is very pugnacious. 

 Bachelor male-, were placed in the vicinity of a mated pair of 

 blue crabs and were beaten away by the vigorous defense of the 

 male in copula. 



Tin- two male blue crabs under observation were tested as to 

 their recognition of females, hard and soft, of the three other 

 specie-. In no case did a male attempt to copulate with an alien 

 female. 



kork L'rahs, (irccn Crabs and Lady Cnihs. These species are 

 all smaller than the blue crabs, and are not materially different 

 in appearance from each other. In the case of the blue crabs, 

 I did not succeed in getting a female with ^permaiophotv plugs. 

 In the case of the three -pecies under present consideration, I 

 did secure M\er,tl o\ igeroiis females that had been ferlili/ed 

 before they were brought into the laboratory, and also M-cured a 

 rock crab \\ ith egg-. 



