REPORT OF COMMISSIONERS OF INLAND FISHERIES. 291 



immediately after the molt, neither the injur}^ involved in the opera- 

 tion nor the resulting regeneration materially affect the length of the 

 molting period. Naturally, therefore, the results for series A^ can 

 not furnish an adequate comparison of the effect of the injury of 

 mutilation with the effect of regeneration, because the mutilations 

 were made too early in the molting period. 



Proceeding next to an examination of the data in Table III, it 

 may be seen that only four of the 23 lobsters in series A4 had not 

 regenerated the chelipeds by the time of molting. The results^ 

 however, for this comparatively small number of mutilated, non- 

 regenerating specimens, are very suggestive. For in this experiment 

 the average length of the molting period for the regenerating lobsters 

 begins to be longer than the corresponding period for the non- 

 regenerating specimens, so that, while the average for the former was 

 14.3 days, for the latter the average molting period was only 13.4 

 days. It may also be noticed that the mutilations in this series of 

 lobsters, instead of being made one day after the molting to the 

 fourth stage, as in series A^, were made four days after the molt; 

 and this suggests that, if there really is a difference between the 

 effects of the injury of mutilation and the effect of mutilation plus 

 regeneration, it ought to become more apparent in mutilations 

 made still latter in the molting period. 



Accordingly, therefore, in passing to the next series of experiments, 

 in which the mutilations were made at various times throughout the 

 entire molting period, it might be expected that a difference between 

 the molting periods for regenerating and the corresponding periods 

 for the mutilated, non-regenerating lobsters would begin to appear; 

 and it is surprising to what extent this is demonstrated in the results 

 for series C4 to C^g. 



It will be recalled that Table V contains the data for both the 

 . regenerating and the mutilated non-regenerating lobsters in series C4 

 to Cjg. From these data the average length of the molting periods 

 for the regenerating and non-regenerating specimens have been taken 

 and arranged as follows: 



