THE BEHAVIOR OF THE SHORE- ANEMONE 313 



slowly accepted by the tentacles of the side first fed. However, 

 these tentacles soon became irresponsive, and the food was 

 offered again to the tentacles of the right side, which had re- 

 acted only once and that fifteen minutes before. These were 

 found to react just as did those of the left side, hanging back 

 from the disk along the column. Jennings concludes as the 

 result of this behavior "that the animal is a unit so far as hunger 

 and satiety are concerned. If the satiety has arisen through 

 the activity of the tentacles of one side, the tentacles of the 

 other side are equally affected by it. It is the general progress 

 of metabolism that is the chief factor in determining the reac- 

 tions to food." In discussing the comparative responses of the 

 hungry and well individuals he says : ' The well fed animal 

 reacts less readily and strongly to simple mechanical shock. 

 If touched with a needle, the well fed individual either does 

 not react at all, or contracts very slightly while the hungry 

 specimen reacts suddenly and powerfully. A slight disturbance 

 in the water has no effect on the well fed individual while the 

 hungry one contracts strongly. To chemical stimuli the same 

 relations apply." 



Allabach (1905) in working on Metridium tried feeding alter- 

 nately pieces of meat and soaked filter paper, not allowing the 

 filter paper to be swallowed. Refusal of the filter paper occurred 

 just as in the cases where it had been swallowed. Thus the 

 effect of the paper after it reaches the digestive cavity cannot 

 be the cause of its rejection. Filter paper was also refused 

 after the tentacles of the same region of the disk had several 

 times accepted meat. 'This result was likewise reached if the 

 animal was not allowed to complete the swallowing of the meat, 

 the latter being removed after it has passed into the oesophagus. 

 This of course shows conclusively that the loss of hunger is 

 not the cause of the change of reaction towards the paper." 

 In a succeeding portion of the paper Allabach says : "It appears 

 evident therefore that it is the reaction of the animal, not the 

 precise character of the stimulus that causes the fatigue. This 

 is perhaps what should be expected when the nature of the 

 food reactions is taken into consideration. In taking food the 

 region in contact with the food produces a very large quantity 

 of mucus, enveloping the food body. It is not surprising that 

 successive immediate repetitions of this excessive production of 



