38 LULU F. ALLABACH. 



thus comes in contact with many other tentacles, these bend 

 down upon it. Then all bend over toward the mouth, while at 

 the same time this portion of the disk contracts. Thus the food 

 is brought nearer the center of the disk. The mouth meanwhile 

 opens, and the food is passed into it, partly by the ciliary action 

 of the tentacles, partly by muscular contractions of tentacles, 

 disk and mouth. The latter factors play a more important part 

 in the reaction of a hungry specimen to a large piece of food than 

 does ciliary action. 



After ten or a dozen good-sized pieces of meat have been 

 swallowed, the reaction becomes much slower. If the meat is 

 brought in contact only with the outer tentacles, these no longer 

 react, and such food is not taken. If placed on the inner ten- 

 tacles, the meat is slowly transferred to the mouth, where it is 

 swallowed. The animal is frequently in this condition when 

 brought into the laboratory ; food placed on the outer tentacles is 

 refused, while that on the inner tentacles is taken. 



The reaction of the tentacles becomes slower as more food is 

 taken, so that the process of ingestion takes a much longer time 

 than at first. Finally, all the tentacles cease reacting to food, 

 and it is not carried to the mouth. But if the meat is placed by 

 the experimenter directly on the mouth, it is ingested. This ap- 

 pears to take place almost alone through the action of the cilia ; 

 the reversal of the cilia seems to be more nearly independent of 

 the physiological states of the animal than are the contractions 

 of the muscles. The mouth never reaches a condition where it 

 rejects pieces of mussel placed directly upon it. So much food 

 may be taken that the body becomes puffed out to form a swol- 

 len sack, yet new pieces are forced inward. Large pieces of meat 

 may however be refused even when placed directly on the mouth, 

 the lack of assistance from muscular contractions appearing to 

 make it impossible for the cilia to draw them inward. The feed- 

 ing may be carried so far as to cause internal disturbance, result- 

 ing in the disgorgement of the food. But immediately after such 

 disgorgement the mouth will take new food. Sometimes when 

 the animal is nearly filled, a large piece of meat placed on the 

 mouth is partly swallowed, then partly disgorged by a convulsive 

 movement, then the swallowing is resumed. This may happen 

 repeatedly. 



