296 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



while a new shell is formed underneath the old one, and when the 

 organizm is ready to molt a split occurs in the shell on the dorsal side 

 of the body, between the carapace and abdomen; a series of laborious 

 movements begin, and gradually the lobster emerges from his old 

 shell. The compact tissues and organs, thus liberated from their 

 unyielding covering, expand and consequently rapidly increase the 

 size of the animal. 



Now, since this increase in the size of the lobster is so clearly 

 correlated with molting, it is evident that whatever condition hastens 

 or retards the frequency of molting must be regarded as an important 

 factor in the growth of the organism. It has been shown in the 

 preceding experiments that the process of regeneration, by retarding 

 the process of molting, tends to diminish the frequency of molting. 

 In view of these facts, therefore, it becomes important to study the 

 effect of regeneration upon the rate of growth of the lobster. 



a. Experiments. 



For the purpose of studying the effect of regeneration upon the 

 growth of the lobster, comparison was made between the growth of a 

 series of normal and regenerating lobsters, through successive molting 

 periods. It is evident that, in order to compare adequately two 

 series of this nature, it is important that the specimens should all 

 be in the same stage and under similar conditions at the beginning 

 of the experiment. At the time when these observations on growth 

 were begun, however, it was so late in the hatching season that the 

 specimens necessary for the present purpose could not be obtained 

 from the hatchery. Accordingly, the only adequate material at 

 hand were the specimens in series B and series C4 to C^g, remaining 

 from the preceding experiments. These, it may be recalled, all 

 molted to the fourth stage on the same night, July 21. Nineteen 

 normal lobsters were available from series B and 36 were obtained 

 from series C4 to C^g. 



Since, in the preceding experiments, the individuals in series B 

 and series C4 to C^g were, respectively, in a normal and regenerating 



