REPORT OF COMMISSIONERS OF INLAND FISHERIES. 185 



ditions. Thus we must conclude that the percentage of increase in 

 the case of Brook's lobsters is slightly less than the normal amount of 

 increase for lobsters of the American species of the same size. Herrick 

 probably approximates more closely to the actual conditions in the 

 table here presented as Table No. 3, wherein he determines 12 per 

 cent, as the average increase for lobsters between 5^ and 11^ inches 

 in length. If we omit, however, the first, second, and seventh speci- 

 mens, an average percentage for the remaining individuals (which 

 represent more closely the size under consideration) drops to 11.4. 

 This, without doubt, represents, with fair accuracy, the average 

 percentage of increase in size for lobsters between 6 and 10 inches in 

 length. 



For lobsters over this size the percentage of increase appears to 

 be further diminished. Two lobsters of the group mentioned in 

 Table No. 3, which were over 11 inches in length, showed an average 

 gain of 10.1 per cent. In three European lobsters mentioned by 

 Williamson ('04), the amounts of increase were as follows: 



12| inches to 13 inches. 



12J inches to 12| inches. 



9i inches to 10^ inches. 



In all other cases of lobsters between 9^ and 12^ inches the amount 

 of increase apparent directly after molting* varied between J and f 

 inches, showing that even the ultimate amount of gain must have been 

 very slight, in all cases under 8 or 9 per cent. We know that the size 

 of the European species is less than that of the American, and ap- 

 parently the average percentage of gain in all stages is consequently 

 diminished. 



2. Application of these Considerations to the Rate of Growth 

 of Lobsters Beyond the Nineteenth Stage. 



Let us return now to the consideration of the average lobster which 



*It usually happens that, if the lobster be measured directly after molting, there is found but 

 a slight difference in length. It requires some little time, usually a week or more, before the 

 lobster attains his full length. 

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