REPORT OF COMMISSIONERS OF INLAND FISHERIES. 171 



larger than those recorded by Herrick^ but that the percentage of 

 increase for nearly all the early stages is greater in the case of the 

 Wickford group. In experiments carried on at Orr's Island, Maine, 

 where the prevailing summer temperature of the water was only 60°, 

 the fourth stage was not attained short of 25 or 26 days ('03). This 

 is over twice as long as the average time required at Wickford to reach 

 the same stage when the prevailing water temperature has been 72°. 

 These facts demonstrate how dependent the rate of growth of the 

 lobster, at different points of the Athmtic coast, may be (at least 

 during the early stages) upon the temperature of the water; hence 

 the difficulty of drawing up any strict account of the rate of growth 

 applicable to all regions. This subject will be considered again on a 

 later page. (See p. 197.) 



A second consideration appears from a ghmce at Tables Nos. 5, 6, 7, 

 and 8. Through the investigations of Emmel ('05) on Homarus it is 

 evident that mutilations of one or more appendages, contrary to the 

 view of Zeleny ('05), exert great influence, not only in delaying the 

 molting periods, but also in diminishing the normal percentage of 

 increase in length in each successive molt. This is shown in the 

 two following tables:* 



♦Whether or not the condition of mutilation and regeneration will decrease the percentage 

 of gain in size at the coming molt seems to be more or less dependent upon the time in the stage 

 period, at uhich the mutilation takes place. The experiments of Emmel ('05) would appear to 

 indicate the fact that the condition of regeneration has less influence upon the rate of increase 

 when the mutilation is performed in the early part of the stage period; and vice versa; that a 

 mutilation performed in the middle of the stage period has a greater influence in diminishing 

 the amount of increase in size at the following molt. 



