158 



REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



Estimating from this table, the average increase in length for the 

 10 stages will be found to be 15.2 per cent. In another group of 66 

 individuals, however, Herrick obtained an average increase of Only 

 13 per cent. It will be observed, however, that, owing to the difficul- 

 ties in maintaining the 7th, 8th, 9th, and 10th stages, the number 

 of individuals in these stages examined is comparatively small; and 

 since the variation in size in a single stage is great, a larger number 

 of observations might perchance give more certain results. It will 

 be observed from Table No. 2 that the percentage of increase under- 

 goes no great variation between stages 1 and 10. 



Other observations were made by Herrick upon lobsters of later 

 stages, and the following table gives records of molts of eight lobsters 

 varying in length from 5^ to 11 J inches. The results demonstrate 

 that, although the percentage of increase for these older lobsters 

 varies between 6.66 and 18.18, the average per cent, of increase is 

 12.01 which, as will be noted, is not far from the per cent, of increase 

 in length for the first 10 stages. (See Table No. 2.) 



Table No. 3. 

 (Herrick's Table No. 24.) Increase in length of lobsters at time of molting. 



♦Recorded by Dr. A. S. Packard, "The Molting of the Lobster," Am. Nat., 1886, XX. 173. 



Taking as a basis the observations presented in the foregoing tables,. 



