216 REPORT OF COMMISSIONERS OF INLAXD FISHERIES. 



XVIII. Summary.* 

 /. The Rate of Growth. 



1. The rate of growth of the lobster is much less rapid than has 

 been estimated by previous observers. 



2. We find the average amount of increase at each molt to be 

 18.4 per cent, for the early stages; and this percentage undergoes a 

 gradual diminution through later successive molts, so that the gain 

 in large lobsters is very slight. 



3. The average female lo])ster lays eggs for the first time in the 

 summer of its sixth year, when in the twenty-third stage. 



4. Beyond the twenty-second stage the male lobster grows more 

 rapidly than the female. This explains the fact that nearly all 

 the "giant" lobsters are of the male sex. 



5. By the time the 9-inch length is reached the male lobster, 

 in Rhode Island or other warm waters, is at least four and one-half 

 years old; the female of the same length, if she has not borne eggs, is 

 about the same age. 



6. . The lobsters in Narragansett Ba}" probably attain marketable 

 size (9 inches in Rhode Island) a year sooner than do the Massa- 

 chusetts or Maine lobsters. 



//. Influences on the Rate of Growth. 



1. The chief influences which iijodify the rate of growth of lobsters 

 are water temperature, food supply, light, and injuries. They are 

 most effective for the early stages. 



2. Temperature is largely responsible for the differences in size 

 of lobsters of the same age in different localities. This results from 



*In addition to the above we would make reference to Table No. 18 which, together with 

 the portions of the foregoing statement which have been printed in itaUcs, embodies the most 

 important facts considered in the exposition. 



