REPORT OF COMMISSIONERS OF INLAND FISHERIES. Ill 



the presence of regenerating structures tends to lengthen the interval 

 between moults. 



Group II contains data on the moulting periods of four fourth and 

 fifth stage lobsters. The right cheliped and second left leg of each 

 lobster were removed about the middle of the fourth stage, but no 

 appendages were removed in the fifth stage. The observations were 

 continued through both stages. The point of interest is that in 

 these specimens when the limbs had not been removed the length of 

 the fifth stage period dropped back to the average of nine and one- 

 haif days, the normal length for the fifth stage. 



It will also be noticed that the average length of the fourth stage 

 was sixteen days; since, however, the length of the normal stage has 

 not yet been definitely determined, it cannot be stated how much 

 longer this is than the normal fourth stage period. 



In conclusion, these results indicate that the presence of regener- 

 ating structures tends to lengthen the interval between moults. 



A series of observations were also made upon the first phase of our 

 question, i. e., whether the rapidity of the regenerating process is has- 

 tened by the approach of the moulting period. This was done by re- 

 moving some of the limbs of about twenty "chicken" lobsters and 

 then making systematic observations and measurements on the re- 

 generating structures. The given appendages were all removed at 

 nearly the same time, about August first. Of course it was not known 

 exactly when the lobsters would moult, but the observations were 

 continued until they did moult and the results then compared to 

 ascertain how the rate or regeneration varied with reference to the 

 length of the interval intervening between the time of injury and the 

 date of the moult. 



The following data on four of these twenty lobsters show the na- 

 ture of the results obtained on the chelipeds and second pair of am- 

 bulatory appendages: 



