154 



REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



X. Further observations on the size, age and rate of growth of "giant " 



lobsters 189 



XI. Summary of observations on the rate of growth 193 



XII. Influences which determine the rate of development. Inherited 



physiological condition 196 



XIII. The influence of temperature 197 



XIV. Regarding the probable difference in the average age of Woods 



Hole and Wickford lobsters at maturity 201 



XV. The influence of light 204 



XVI. The influence of body parasites and secondary effects of light 207 



XVII. The influence of food supply 208 



XVIII. Summary 216 



XIX. Bibliography 218 



XX. List of tables 222 



XXI. Presentation of plates demonstrating some stages in the develop- 

 ment of the lobsters from time of hatching to attainment of 

 very great size 223 



I. Introduction. 



At a time when artificial propagation is bidding fair to partially 

 check the ever increasing depletion of many forms of marine animals 

 whose economic value has long sustained a many-sided fishing in- 

 dustry, any facts which may bear directly or indirectly upon the life, 

 habits, or development of such forms might seem to be of value. 

 This fact is especially true in respect to the, American lobster, a 

 knowledge of whose development must influence not only methods of 

 artificial propagation, but also legislation in determining the season 

 and size at which the taking of lobsters shall be allowable. 



It may here be noted that the life of the lobster from time of hatching until 

 time of death is but a series of stages or stage periods, so-called, each one of 

 which represents a period of its life between any two successive molts or 

 castings of its shell. Of these stages, the first four are passed through 

 rapidly, the young creature molting usually four times in the first twenty 

 days of his existence. It is these first few stages, so quickly passed, that 

 include the most important changes which the young lobster undergoes, and 

 they are called the larval stages, denoting the successive emergence of one 

 form from another. In each successive stage the lobster is larger than before ; 



