198 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



Table No. 19. 



Showing the effect of variation of temperature upon the rate of development of 

 lobster fry of the first three stages at Wickford, R. I. 



Experiment. 



Duration of the First Three Stages. 



Average 

 Temperature. 



1 



2 

 3 



4. 

 5. 

 6, 

 7. 

 8 

 9 

 10, 

 11 



16 days 

 15 days 

 13 days 

 13 days 

 13 days 

 10 days 

 12 days 

 12 days 



10 days 

 9 days 



11 days 



65° F. 

 66° F. 

 68° F. 

 68° F. 

 69° F. 

 70° F. 

 72° F. 

 72° F. 

 72° F. 

 72° F. 

 73° F. 



The following table, compiled from data furnished by my friend 

 V. E. Emmel, demonstrates readily the difference in the rates of 

 growth of two groups of lobsters in the fourth stage at different 

 periods of the summer. It is readily observed that the period of 

 least rapid growth is contemporary wath the time of lowest water 

 temperature. 



Table No. 20. 



Showing the differences in the rate of development of two groups of fourth stage 

 lobsters under different conditions of water temperature. 



We would, in this connection, call attention to the very much less 

 rapid development of lobsters in these same stages at the hatchery 



