96 COMMISSIONERS OF INLAND FISHERIES. 



5. MOLTING AND GROWTH. 



Covered by a hard shell, the only means which the lobster has of 

 becoming larger is by casting off its old shell; that is, by molting. 

 Growth has already taken place within, rendering the animal more 

 compact, so that when the lobster sheds it immediately expands 

 through the absorption of water. (Plate VI.) The new shell, at 

 first as soft as wet paper, becomes hardened in a few days and pre- 

 vents further expansion. The lobster in the first year, molts about 

 14 or 15 times. Each successive year it molts less often until lobsters 

 between 8 and 9 inches long shed no more than 2 or 3 times a year. 

 Concerning the molting periods of larger lobsters, scarcely anything 

 is known. 



It is known, however, that — 



1. When regeneration of various parts is taking place, the molting 

 period and presumably the growth will very often be retarded. 



2. Excessive light (as rearing in cars without covers), will lessen 

 the percentage of gain at each molt, and perhaps of the periods. 



3. Abundance of food will increase the percentage of gain and 

 perhaps hasten the molt. 



G. REGENERATION. 



If a claw or any appendage is lost the lobster has the power of grow- 

 ing it again (regeneration). (Plate VII.) Should the loss occur 

 within a certain period, too near an approaching molt, the molting 

 occurs regularly without anything being done in the way of repair. 

 If, however, the loss happens a considerable length of time before the 

 molt, this period will be delayed somewhat, and, in place of the lost 

 limb, a bud will grow out. When the molt occurs the lost limb will 

 come out fully formed, but about one-half size. When the next 

 molt occurs it will be full size. This is true, with some variation, of 

 all external organs unless it is the eye. This has never been observed 

 to regenerate at the experiment station. Closely related to this 



