REPORT OF COMMISSIONERS OF INLAND FISHERIES. 

 Table No. 3. 



255 



Showing the relative effects of sunlight and twilight upon the increase in the size of 

 lobsters molting from the fourth to the fifth stage* 



* All lobsters recorded passed from the third to the fourth stage on the same day, June 23, 

 and were thus subjected to the same degree of water temperature whose variation, as we 

 know, is able to make a great difference in the duration of the stage-period, as also in the 

 amount of increase in size. Food conditions were also identical in the case of each group. 



Other observations from which we are able to determine a difference 

 in the rate of growth are those from the experiments of Mr. V. E. 

 Emmel, who kept many young lobsters through out the summer of 

 1905 in wire cylinders similar to those already described. In this 

 case there was a partial protection afforded by stretching a framed 

 canvas somewhat above the wire cages in which the lobsters in ques- 

 tion were confined. Here, it is interesting to note, we find the dura- 

 tion of the fourth, fifth, sixth, and seventh stage periods from one 



