41 



horizontal direction, and for the capture of minute floating 

 particles of food, abundant during the summer months. 



Later, free swimming stages succeed these, but whether 

 they are numerous and last for weeks or months is not yet 

 known. These free swimming forms are glassy and trans- 

 parent and swim about rather slowly and without the timidity 

 which characterises later stages. Probably their transparency 

 helps them to avoid their enemies. 



Ultimately, however, these free swimming forms settle down to 

 the bottom, lose their swimming appendages, and seek refuge 

 in seaweed and rocks in the shallow parts of the sea, avoiding 

 as best they can the numerous enemies of this stage. It is no 

 longer transparent and invisible to its enemies, and is timid 

 and wary in its movements. The body becomes opaque and 

 pigmented. The inner branches of the walking legs come into 

 use for the first time as organs of locomotion, and it can 

 crawl into crevices ; the outer swimming branches are lost. 

 The tail region increases very considerably in size and forms 

 a powerful organ of locomotion, as, by its sudden flexure, it 

 is capable of projecting the body backwards at a rapid rate, 

 away from any suspected source of danger. 



As it increases in size with succeeding moults the animal be- 

 comes better able to defend itself, and it may venture further 

 afield. 



The remaining stages of its life history differ according to 

 whether it is a male or female. 



During or towards the end of the winter months the female 

 casts her shell and soon after has connection with the male, 

 and lays the eggs which become attached to the underside 

 of the tail. 



The eggs are carried about in this way for some months 

 and the female finds her way into shallow water, the male 

 into deep water. 



In the early summer months the eggs of the female, which 

 is then in shallow water among seaweed, hatch out. 



Meanwhile the males in the deeper water begin to cast 

 their shells and gradually to build up a new one. They are 

 then in poor condition, being described by the fishermen as 

 " sick," and are unfit for food. This lasts till about the end 

 of January or the beginning of February, when the fish have 

 fully acquired the new shell, and the body fills up so that they 

 are described as in " good condition " by the fishermen. 

 During this sick condition they apparently do not eat much 

 and are scarcely to be tempted by bait, finding shelter in 

 crevices of the rocks or burving themselves in sand. 



[C.P. 5-'i3-] 



