REPORT OF COMMISSIONERS OF INLAND FISHERIES. 271 



normal molting period by 18 per cent.; on the other hand, in the 

 mutilations made one day after the molt, the resulting regeneration 

 only increased the rate of molting by the small amount of 1§ per 

 cent. 



This marked difference in the results suggests the importance of a 

 more careful study of the effect of introducing the process of regenera- 

 tion at different times throughout the molting period. 



a. Experijnents. 



The general plan of the following experiments was to select a large 

 number of lobsters which are equal in age, are in the same stage, are 

 approximately equal in size, and in a normal condition; to separate 

 these specimens into two groups; the one for mutilation, and the 

 other to be retained in a normal condition to serve as a control; 

 then to subdivide the former group into a number of smaller groups 

 and to mutilate the lobsters in these sub-groups at several different 

 times. 



A more detailed description of the experiments is as follows: 

 On July 21, 1905, at 9 A. M., 160 lobsters were selected which had 

 molted to the fourth stage during the preceding night. Only those 

 individuals were selected which were nearly equal in size and in a 

 normal condition. Sixty of these specimens were reserved as con- 

 trols; the remaining 100 specimens were subdivided into ten groups 

 of 10 lobsters each. Four days after the molt, on July 25 at 9 A. M., 

 the lobsters in one of these ten sub-groups were mutilated. The 

 mutilation consisted in causing the removal of both chelipeds. On 

 each succeeding day, at as nearly the same time (9 A. M.) as was 

 possible, a similar operation was performed on another of the remain- 

 ing sub-groups. Thus these ten mutilated groups of lobsters were 

 arranged in a series characterized by a difference of one day in the 

 time of mutilation in each case. 



For convenience in discussion the normal group will be desig- 

 nated as series B; and the mutilated groups as series C4, C5, Cg, 

 C7, Cg, Cg, CjQ, C^j, C12 ^^d C13. The series numerals in each case 



