THE AMERICAN LOBSTER. 81 



It is stated in the animal report of the inspector of fisheries of Prince Edward 

 Island {209, p. 23(5) for 1880 that soft-shell lobsters " are seldom seen on the north side 

 of the island, while on the south side almost all that are caught in the month of July 

 are soft and unfit for canning." A cauner in Queens County says that scarcely a 

 lobster can be caught before the 20th of May. Soft-shell lobsters begin to abound by 

 the 1st of August and continue abundant during this month. One-third of the lobsters 

 caught during August are said to be soft-shelled. The fishery officer for Gape Breton 

 states in his report for 1S88 (210) that no soft-shell lobsters were captured during the 

 fishing season which closed July 28. 



THE MOLTING PROCESS. 



Next to reproducing its kind, the act of molting is the most important in the life 

 of this animal. The whole body is covered, as we have seen, by a chitinous shell, in 

 which salts of lime are deposited, giving to parts of it the hardness of stone. Molting 

 consists of two distinct phenomena: (1) the formation of anew shell and (2) the rejection 

 of the old. When once formed the shell admits of no increase in size, since it is a 

 dead structure, excreted by the skin below it, and when it is outgrown it must be 

 cast off and replaced by a new and larger shell. The new shell is gradually excreted 

 under the old one, and when the latter is discarded the new shell is soft and flexible 

 and is easily distended to meet the requirements of growth. The growth of the lobster, 

 and of every arthropod, thus apparently takes place, from infancy to old age, by a series 

 of stages characterized by the growth of a new shell under the old, by the shedding of 

 the outgrown old shell, a sudden increase in size, and the gradual hardening of the 

 shell newly formed. Not only is the external skeleton cast off in the molt and the 

 linings of the masticatory stomach, the oesophagus and intestine, but also the internal 

 skeleton, which consists for the most part of a complicated liukwork of hard tendons. 

 This is rendered possible from the fact that these structures are derived from infolded 

 portions of the skiu, and in molting they are simply drawn out of their original folds 

 or pockets. It is thus easy to see why the molting process is critical. 



The frecpiency of the molting period depends directly upon the physiological 

 condition of the animal, which varies with its environment. The molting process is 

 both an expensive and dangerous operation, and calls for a considerable excess of 

 energy. Since it is largely dependent upon the condition of the individual, which is 

 subject to wide variation, the molt does not take place at any stated time, but may 

 occur in any month of the year, though but rarely in the spring. Warmer weather, a 

 more active life, and a more vigorous appetite, which are characteristic of the lobster 

 during the warmest part of the year, are most favorable, as we have seen, to the 

 renewal of the shell. The lobster, though a carnivorous and voracious animal, 

 feeds less in winter, when its habits are relatively sluggish. Broken limbs and 

 injuries to the shell are then but slowly repaired, and there is less energy to be 

 drawn upon in molting. 



The growth of the crustacean takes place during the period of the molt, while the 

 new shell is being formed, and not immediately after the ecdysis, as is commonly 

 believed. It was clearly shown by Vitzou that the old shell is gradually thrown off 

 in consequence of the growth during the molting period, when the animal tends to 

 become larger than its envelope. The rapid swelling out of the body after the old 

 shell is gotten rid of is due to the absorption of water through the new shell into the 

 blood and tissues, not to cellular growth. 



F. 0. B. 1895—6 



