456 H. S. 'Jennings. 



mouth, while the surrounding tentacles may quite omit their 

 reaction. The food body is not placed so accurately upon the 

 mouth as in the hungry individual. At a further stage toward satia- 

 tion, a piece of crab meat applied to the tentacles induces either no 

 reaction at all or a straight withdrawal — a negative reaction; 

 they may then bend back from the disk along the column. If the 

 meat is placed directly on the disk, in contact with the mouth, the 

 latter may very slowly open and in a languid way partly or entirely 

 enclose the food, even w^hen there is no reaction of the tentacles. 

 The mouth is thus usually readier to give the food reaction than 

 are the tentacles. 



In this condition of approaching satiation some peculiar com- 

 binations and alternations of positive and negative reactions may 

 be observed. In a specimen of Aiptasia No. 2 after five pieces of 

 alternate meat and paper had been taken, another piece of paper 

 was swallowed, then after one and one-half minutes this was 

 disgorged. The disgorged piece lay on the disk for a few seconds, 

 then the mouth opened and began swallowing it again. But after 

 it was about half enclosed, it was again rejected. Now it was 

 grasped again and partly re-swallowed, then again rejected. This 

 performance was repeated once more before this piece of paper 

 was definitely rejected. A fresh piece of paper presented imme- 

 diately after was slowly swallowed, then in two minutes disgorged. 

 The anemone presented exactly the spectacle which we should 

 interpret in a higher organism as a struggle between desire and 

 repugnance for the available food. 



In another case a piece of meat was presented after six pieces 

 had been swallowed. The tentacles reacted only very slowly, 

 but finally deposited the piece of meat on the disk, and withdrew. 

 The mouth opened part way, then closed again without ingesting 

 the food. Later it opened again a very little and enclosed a 

 minute shred of the meat between its lips. The piece was thus 

 quietly held for ten minutes, when it was seen to be sinking imper- 

 ceptibly. Fifteen mmutes after it was given it was completely 

 enclosed. Many other cases were seen of partial rejection and 

 acceptance of the same piece of meat. At times after one piece 

 has been rejected, another is accepted. 



In Adamsia and Metridium, according to Nagel ('92) and 

 Parker ('96), after the tentacles of a certain region of the disk 

 have through repeated trials come to reject soaked filter paper, 



