THE BEHAVIOR OF THE SHORE-ANEMONE 327 



algal cells in the endoderm of the column wall, mesenteries, 

 and tentacles probably tends to make such behavior adaptive 

 in character. 



There seems to be no impressed diurnal or tidal rhythm in 

 specimens of Cribrina removed to the laboratory; for when 

 placed under uniform illumination this species remains expanded 

 for several days continuously, and when subjected to darkness, 

 contracts and remain contracted for a like period. 



In their native environment, all of the anemones examined 

 appeared to be hungry, and in many cases, quite readily swal- 

 lowed apparently clean objects such as stones. The food of 

 Cribrina was ^ound to be very varied in its kind. 



The introduction of a solution, two parts of beef juice to 

 eight parts of sea water, into the gastrovascular cavity of the 

 anemone produced a copious secretion of mucus, accompanied 

 by a lowered responsiveness of the organism. Food offered to 

 the tentacles of an anemone so treated was rejected. 



Much the same reaction, though to a less degree, was secured 

 upon the application of a concentrated extract of fresh oyster. 

 A quite marked mucus secretion and a proportionate degree 

 of depression was produced upon treatment with both potassium 

 chloride and mercuric chloride. 



Solutions of sodium chloride and lithium chloride isotonic 

 with the potassium chloride were found to produce only negli- 

 gible effects upon the anemones treated. The tentacles of these 

 accepted food immediately upon the expansion of the anemone. 



Muscular fatigue seems to be of little importance in the modi- 

 fied responsiveness to food. 



It was found possible to produce a condition of irresponsive- 

 ness to food on the part of the tentacles by feeding these large 

 pieces of oyster successively and not allowing this meat to be 

 swallowed. 



The altered behavior in relation to food on the part of the 

 tentacles seems to be due to the lowered responsiveness accom- 

 panying mucus secretion. This depression is perhaps caused 

 by the disturbance of the balance of nutrition in the cell; per- 

 haps as the direct effect of the substance employed on the neuro- 

 fibrillar system of the anemone. 



The evidence seems to warrant the conclusion that the modi- 

 fied behavior in relation to food is due rather to a gradual decline 



