REPORT OF C0MMISSI0NP:RS OF INLAND FISHERIES. 39 



Observations and Experiments on Individual Specimens in 1904. — 

 In order to study the growth of individual lobsters and possibly to 

 account for discrepancies in rate of growth, color, etc., and in order, 

 furthermore, to study the effect of foods, of loss of claws and regener- 

 ation and many similar questions, a large number of fourth and fifth 

 stage lobsters were last summer placed in separate compartments. 

 Each lobster was given a compartment, and a separate record of each 

 lol)ster was kept until the cars were sunk to the bottom in November. 



The lobsters usually selected were in the fourth stage, although it 

 became necessary to take some which had come into the fifth stage. 

 The individual cars were numbered and the lobsters were examined 

 usually two or three times a day in order to keep strict account of the 

 moulting process, color changes, etc. These experiments were at- 

 tended with some difficulties. At first a high rate of mortality oc- 

 curred without apparent cause. It was soon discovered that the 

 pine wood, of which the sides of the car were made, caused the death 

 of the lobsters, although the cars were closed at the end with wire 

 netting only and the compartment partitions were of the same ma- 

 terial. Cypress or spruce was better, but the lobsters demand a very 

 free circulation of water. This is remarkable in view of the fact that 

 lobsters of this age will sometimes live for weeks in a small dish in 

 which the water has not been changed. 



The mortality was especially great at the time of moulting. 

 These are, without doubt, critical periods, and, when a lobster is 

 somewhat weak, are usually fatal. A large number of these speci- 

 mens died when the skin was partly shed. When all goes well, the 

 moulting is accomplished in a very few minutes, and in a very few 

 hours the skin is destroyed — probably eaten by the former wearer. It 

 is necessary to keep very close watch of the lobster during the fifth, 

 sixth, seventh, and eighth stages, if one wishes to collect the whole 

 skin. In some of the later stages the lobster tries to bury the cast 

 skin. Nor infrequently young lobsters have difficulty in freeing the 

 claws, and sometimes break off the claw autotomously and leave it 

 in the shell. We have several casts which contain a claw broken 



