FIDDLER CEAB — HYMAN. 459 



more independent of the moisture of the immediate water's edge and 

 he may wander about more freely on the beach. The eyes are also 

 provided with a joint and an erectile muscle at this time so that they 

 may be raised upright over the carapace like two periscopes and car- 

 ried in this position which is so characteristic of beach crabs. The 

 abdominal appendages are not fully differentiated, but they show 

 clearly all the parts that will form the sexual appendages of the 

 adult. The young crab after this lives just like the adult. It gets 

 its food from the sand on the beach, digs its burrow between the 

 tide lines, comes out and feeds when the tide is falling, and hides in 

 its burrow when the tide is coming in. It continues to grow, and as 

 it grows continues to molt time after time. Of course, as the crab 

 grows larger it digs a deeper and larger burrow. 



During the remainder of the summer and the early autumn the 

 young crabs continue to grow and molt and grow again. The colony 

 on the beach is always being recruited by late arrivals from the sea, 

 because the breeding season of fiddlers is a long one, beginning in 

 early spring and extending through the summer and on into Sep- 

 tember. Besides their increase in size, each sex undergoes a slow 

 transition to its sexually mature conditions. In the males the great 

 claw becomes disproportionately larger and larger. It retains its 

 juvenile shape, with its short, thick parts, until the young crab is 

 about a year old. Then, with the completion of sexual development, 

 the hand and the fingers lengthen to form the threatening claw of the 

 adult male. The chief change in the female is in the abdomen. 

 This gradually gets broader and broader until it fits over the under- 

 surface of the body like an apron. It is becoming better and better 

 fitted to serve as a support for the great batch of eggs that will later 

 be attached to the swimmerets. 



When the weather begins to get cold in the late autumn all the 

 crabs on the beach crawl into their burrows for the winter hiberna- 

 tion. The unlucky larvae and little crabs that are not yet strong 

 enough to dig their burrows perish of exposure during the first cold 

 weather. All during the winter the crabs remain buried. If there 

 comes a period of warm sunny weather lasting several days, how- 

 ever, a few individuals may come out and run about on the beach. 

 They can not get much food now, because the surface of the sea 

 is not teeming with life as in the warm summer and the sand " wind- 

 rows " of the beach are little more than sand. 



As soon as the first warm weather comes in spring all the little 

 fiddlers become lively again and dig themselves out. Some of the 

 young crabs of the preceding summer may have become sexually 

 mature by this time and by early April they lay their eggs, and soon 

 the sounds and adjacent sea are receiving new swarms of delicate, 

 active zoeas, setting out upon the great adventures through which 

 every fiddler crab must pass in its youth. 



