200 



REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



The temperature has a marked effect, not only upon the frequency 

 of molting, but also upon the relative increase in size per niolt. This 

 result is reached, no doubt, by the stimulation or lack of stimulation 

 of the general metabolic processes which seem to be checked by an 

 unfavorably low temperature, as is the case during the cold winter 

 months. A better conception of the outcome of these circumstances 

 may be obtained by observing the data presented in Table No. 6, 

 although all the facts which have been recorded to demonstrate the 

 difference in size (stage for stage) of the Woods Hole and the Wick- 

 ford lobsters have an important bearing in this connection. It is, 

 moreover, often noticeable that one stage-period in the early develop- 

 ment of the lobster may be briefer, instead of longer, than the stage- 

 period preceding. This has usually been observed in connection with 

 the fourth and fifth stage- periods. No reason has previously been 

 given to account for this phenomenon. In these particular instances, 

 however, it is clear that the unusually brief stage-periods are coinci- 

 dent with the period of maximum water temperature. For illus- 

 tration attention may be directed to Tables Nos. 5, 6, and 25. Here 

 it is seen that, though the fifth stage-period for the normal 1904 

 lobsters is 9.5 days, the fourth stage-period is 12 days. Records show 

 that the highest prevailing temperature for the summer of that year 

 occurred between Julv 11th and 23rd, which was the time when the 



