REPORT OF COMMISSIONERS OP INLAND FISHERIES. 293 



series; also the length of each line corresponds to the number of 

 individuals. It will also be observed that the elevation of the lines 

 in each section, with reference to the normal level for series B, 

 indicates the extent to which the average molting period has been 

 lengthened or shortened in each case. 



Now if the injury due to mutilation is as great a factor as the 

 process of regeneration in lengthening the molting period, it would 

 be expected that the general elevation of the dotted lines above the 

 normal standard would be approximately equal and be practically 

 coincident with the general level of the heavy broken lines. But it 

 is readily seen that such is not the case; for the general levels of the 

 dotted lines remain comparatively close to the normal standard. 

 Consequently, instead of beginning at the left and taking a course 

 coincident with the level of the broken lines in each section, the 

 dotted lines or non-regenerating levels begin at the left and steadily 

 diverge from the broken lines or regenerating levels, and the majority 

 of the dotted lines even lie below the normal. In other words, the 

 average length of the molting periods for the mutilated non-regenerat- 

 ing individuals is not only shorter than the periods for the regenerat- 

 ing specimens, but in the majority of cases the non-regenerating 

 period is even shorter than the normal molting period. 



Thus this graphical representation most clearly emphasizes the 

 general character of the data; and the results of these experiments 

 prove that the injury of mutilation alone does not, in general, 

 materially lengthen the molting period. Therefore it seems evident 

 that the injury due to the act of mutilation can not, to any great extent, 

 account for the increase in the length of the molting period 'produced by 

 the process of jr generation. 



6. 



The Influence of the Molting Process upon the Regenerative 

 Process in Regard to its Response to Mutilation. 



So far in the present study of the relation of regeneration to the 

 molting process only one phase of the problem has been considered, 



