326 G. H. TARKER 



bits of detritus and the like become entangled among the distal 

 tentacles, whence they are transferred to the mouth. The 

 proximal tentacles seem to play a very minor part in this type 

 of food gathering. Records on a single individual showed that 

 in one hour twenty feeding movements were made. Of the 

 three minutes involved in each interval, for the intervals were 

 very regular, about one minute was taken up in the actual feed- 

 ing movement and about two in rest. 



When a Corymorpha that has been exhibiting a regular se- 

 quence of feeding movements in quiet water is subjected to a 

 current of water, these movements cease at once, to begin again 

 a few minutes after the current has been cut off. Apparently 

 this type of response in normal animals is dependent upon 

 quiet water. 



If a Corymorpha that is feeding regularly in quiet water, is 

 deprived of its hydranth by having it suddenly clipped off at 

 the neck by scissors, the stalk continues the feeding responses 

 but without bowing low enough to bring its distal end close to 

 the substrate. In this sense the response is defective and, as 

 the following record shows, it is also slower than before. A 

 normal polyp was found to carry out feeding responses at the 

 following intervals in minutes, 3.5, 3.5, 2.5, 2.5; whereupon 

 its hydranth was cut off and the stalk continued to respond at 

 intervals in minutes of 5, 4, 5, 4.5, and 5, when the experiment 

 was concluded. 



Another curious effect of beheading a polyp was seen in 

 experiments with pairs of feeding individuals. A pair of polyps 

 regularly feeding in quiet water were watched for a short time 

 and then the hydranth of one was cut off; both individuals the 

 one without a hydranth as well as the one with a hydranth con- 

 tinued to carry out bowing movements. The circulating current 

 in the aquarium was then turned on whereat the normal in- 

 dividual ceased to respond while the headless one continued to 

 carry out rhythmic bowing movements. This experiment was 

 often repeated and with uniform results. The water currents 

 in some way stimulate the whole animal so as to cause the feed- 

 ing responses to cease, a condition that does not obtain in the 



