SEA-FISHERIES LABORATORY. 413 



the above experiment on May 14th, 1913. No 

 daily analyses of oxygen and carbon-dioxide were 

 made as previous research supplied the necessary 

 information on this point, and the object was to make as 

 prolonged an experiment as possible. The water was 

 changed daily throughout the entire period of over seven 

 months that this experiment lasted, so that each animal 

 had an allowance daily of 40 to 50 litres of fresh sea- 

 water. The four carboys were kept covered up from the 

 light by tarred black canvas covers throughout the dura- 

 tion of the experiment, except during the few minutes 

 each morning when the water was being changed. 



The complete duration of the experiment was from 

 May 14th, 1913, till January 4th, 1914, a period of 235 

 days. Two of the animals (Nos. 1 and 4) lived throughout 

 the entire period, and weighed as much at the end as at the 

 beginning, the other two died while shedding their shells, 

 one early in the experiment on June 14th, 1913, the other 

 (No. 3) nearly at the end, on November 14th, 1913. The 

 lobster which died on June 14th was omitted from con- 

 sideration, and replaced by another (No. 2) on June 18th, 

 and this animal remained alive and active till the end of 

 the experiment, on January 4th, 1914. The weights of 

 the animals during the experiment were as follows : — 



Lobster No. 1 : May 14th, 1913, weight, 3019 grams; 

 June 14th, 1913, weight, 3034 grams; January 4th, 1914, 

 weight, 301 '7 grams. 



Lobster No. 2: June 18th, 1913, weight, 271 grams; 

 January 4th, 1914, weight, 270'5 grams. 



Lobster No. 3: May 14th, 1913, weight, 2207 grams; 

 June 14th, 1913, weight, 2235 grams. (Died November 

 14th, 1913). 



Lobster No. 4: May 14th, 1913, weight, 2247 grams; 

 June 14th, 1913, weight, 2273 grams; January 4th, L91 I, 

 weight, 226'4 grams. 



