28 THE LIFE OF CRUSTACEA 



eggs in this way is said by the fishermen to be " in 

 berry," and may carry, according to its size, from 

 about 3,000 to nearly 100,000 eggs. A period of 

 about ten months elapses between the deposition 

 of the eggs and hatching. 



The young Lobster when first hatched (Fig. 8) 

 differs considerably in general appearance from the 



adult animal. The 

 abdominal somites 

 have a row of spines 

 down the middle of 

 the back, and the 



FIG. 8 FIRST LARVAL STAGE OF telson has a forked 

 THE COMMON LOBSTER, x 4. cV, ane There are nn 

 (After Sars.) na P e< * nere are E 



swimmerets, but, as 



already mentioned, the legs bear large exopodites, 

 which are used like oars, and by means of these 

 the larval Lobster swims about at the surface of the 

 sea. The claws or chelae are at first hardly larger 

 than the other legs, but later they increase in size, 

 the swimmerets are developed, the exopodites of 

 the legs are lost, and the young Lobster, sinking to 

 the bottom of the sea, takes on the creeping habits 

 and gradually assumes the shape of the adult. 



In many Crustacea the changes of shape or meta- 

 morphoses undergone after hatching are much 

 greater than in the Lobster. Some of these changes 

 and their probable significance will be considered at 

 greater length in a later chapter. 



