24 ABOUT LOBSTERS 



above. It is only when the lobsters are turned on their backs 

 that their differences become evident. 



In the male lobster the two swimmerets nearest the cara- 

 pace (the solid shell) are hard, sharp and bony, whereas in 

 the female the same swimmerets are soft and feathery. The 

 difference is clearly noticeable either by sight or feeling. 

 When the female is impregnated by the male, his semen is 

 deposited in a pocket in the underside of his mate's body. 

 This receptacle appears as a shield wedged between the 

 bases of the third pair of walking legs. Its function is to 

 hold the sperm until the eggs leave the body and are ready 

 for fertilization. 



Mating. The female is always impregnated by the male 

 while she is soft shelled, and often within a few hours after 

 molting. When the female is ready to accept her mate it is 

 believed she searches him out. Anderton in The Lobster 

 describes the process: 



Two hours after molting, she was seen roaming 

 round the pond and frequently approaching the various 

 shelters, returning regularly and fearlessly to a shelter 

 containing a large male. On approaching the entrance 

 to this shelter the large claws were extended in a direct 

 line with the body and the antennae were thrust within 

 the shelter. After a few moments the beak of the male 

 appeared, the female meanwhile rapidly whipping her 

 antennae across the now projecting beak of the male, 

 which in turn showed increasing signs of excitement, 

 his antennae being whipped very rapidly over the fe- 

 male in the same manner. After an interval of perhaps 

 a minute the male gradually withdrew from his shelter, 

 the female at the same time turning over on her back to 

 receive him. The sexual act took place at once, occupy- 

 ing only a few seconds, the male retiring at once to its 

 own shelter and the female into another. The following 

 day both were observed to be living in one shelter, and 

 they continued to do so, on and off, for several weeks. 



