REGARDING THE RATE OF GROWTH OF THE AMERICAN 

 LOBSTER, 



(HOMARUS AMERICANUS). 



PLATES XXVI TO XXXVII. 



PHILIP B. HADLEY, 

 BROWN UNIVERSITY, PROVIDENCE, R. 



CONTENTS. 



I. Introduction 154 



II. Earlier observations on the rate of growth 156 



1. Amount of increase at molt 156 



2. Frequency of the molting period 159 



III. General observations upon the European lobster {Homarus vulgaris) 160 



IV. Observations at Wickford on the first ten stages of Homarus ameri- 



canus 164 



V. Possible explanation of the variations in the rate of growth of lob- 

 sters mentioned in the tables 170 



VI. Observations on the rate of growth of lobsters beyond the 10th stage 173 



VII. Observations on the rate of growth of lobsters over one year old .... 178 



VIII. Observations on the rate of growth of lobsters over two years old . . . 180 



1 . Gradual diminution in the percentage of increase at molt 



for lobsters beyond the 18th stage 181 



2. Application of these considerations to the rate of growth 



of lobsters beyond the 19th stage 185 



IX. Differences in the rate of growth of male and female lobsters 186 



1. In the case of lobsters under 11 inches in length 186 



-2. In the case of "giant" lobsters. Chances of life for 



the adult female. Legislative considerations 188 



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