THE BEHAVIOR OF THE SHORE-ANEMONE 317 



Potassium chloride. — (Normal solution in sea water and 3/8 

 normal in distilled water.) Thorough injection produced a 

 copious mucus secretion. At end of two hours specimens had 

 not expanded, but the tentacles were almost totally irrespon- 

 sive. When a piece of oyster is placed over the mouth, the 

 bladdery lobes of the stomodaeum were extended and the food 

 taken in. The following morning the tentacles had recovered 

 almost normal responsiveness to contact stimulation, but still 

 refused food given to them. At four o'clock of the same day 

 the tentacles slowly accepted food offered them. The second 

 day after the experiment, the anemones in many cases accepted 

 food quickly, and the most of them seemed in every way, so 

 far as discernible, entirely normal in responsiveness. 



In the case of the 3/8 M KG in distilled water, a solution 

 practically isotonic with sea water, the anemone in three cases 

 out of six slowly accepted food after injection and subsequent 

 expansion. The mucus secretion upon treatment with this 

 strength of solution was not nearly so copious as in the case of 

 the normal solution. Consequently I am led to believe that 

 the number of potassic ions present was not sufficiently an 

 excess to produce an exhaustion of the mucus secretion of the 

 tentacles adequate to prevent the acceptance of food by these 

 through their lowered responsiveness. This view is strength- 

 ened by the fact that 5/8 M KC1 + 1/3 M KC1 did produce a 

 condition to all effects the same as that produced by the normal 

 solution of potassium chloride used. This solution of potas- 

 sium chloride contained a larger number of potassium ions than 

 did the solution isotonic with sea water. The fact that it is 

 a solution hypertonic to sea water is not of significance, I believe, 

 since a solution of sodium chloride of the same strength effects 

 no change in food response. This is also an indication that the 

 potassium ions are the factor producing the secretion of mucus 

 and not the chlorine ions. 



Mercuric chloride. — (0.2 per cent solution in sea water.) A 

 thorough injection produced a very marked secretion of mucus 

 apparently from all of the surfaces of the body. The individual 

 was killed as the result of this injection, even though the sea 

 water was changed immediately. Where a partial injection was 

 secured into the gastrovascular cavity at fifteen minutes past 

 nine in the morning, at noon response of the tentacles was 



