408 



L. H. HYMAN. 



that differences in muscular activity could account for the 

 decrease I oxygen intake in the presence of cyanide. As far 

 as could be determined, the hydranths were as fully expanded 

 in the presence of cyanide as in normal sea-water. 



EXPERIMENTS ON METRIDIUM. 



Metridium marginatum was selected as a representative of the 

 Anthozoa. The individuals used had probably been kept in float 

 cars for some time. Medium-sized individuals were placed in 

 wide-mouthed bottles of about 600 c.c. capacity, one in each, and 

 left there undisturbed until they had attached themselves and 

 expanded fully. It was found that the animals soon became 

 accustomed to such an environment and could be handled and 

 would submit to change of water without contracting. Since 

 the oxygen consumption of sea-anemones in all probability varies 

 with the degree of expansion, note was always made of the degree 

 of expansion during the experiments. In experiments I and 3, 

 the animals were slightly contracted during the exposure to 

 cyanide but in the other six experiments they were fully expanded 

 throughout. Differences in state of muscular activity are 

 therefore not responsible for the observed results. 



The eight experiments which were performed upon Metridium 

 are reported in Table II. A marked and reversible decrease in 

 oxygen consumption in the presence of cyanide was found in all 

 cases. 



TABLE II. 



ACTION OF POTASSIUM CYANIDE ON THE OXYGEN CONSUMPTION OF 



Metridium marginatum. 



Oxygen Consumed, Cubic Centimeters per Hour. 



