328 G. H. PARKEE 



The food accumulated by the two methods mentioned in the 

 preceding paragraphs doubtless undergoes digestion in the gas- 

 trovascular cavity of the polyp and is moved about in this 

 cavity by the peristalsis of the proboscis already referred to. 



8. GENERAL CONCLUSIONS 



When the responses and activities of Corymorpha are com- 

 pared with those of an anthozoan polyp, their inefficiency is 

 most striking. This is especially well seen in the tentacular 

 responses to food. In an anthozoan the tentacles when touched 

 by a piece of food turn in many directions till they have more 

 or less entwined the food. They become covered with a sticky 

 mucus and they discharge their nettling filament with great 

 freedom. Finally by the action of their cilia and muscles the 

 food is delivered at the lips. In Corymorpha the proximal ten- 

 tacles are not provided with mucus and their one muscular 

 response is to wave toward the mouth, a response that occurs 

 as well when the food touches their aboral faces, and is conse- 

 quently left behind by their response, as when it is on their 

 oral face No cilia are present in Corymorpha to help trans- 

 port the food to the mouth. In Corymorpha the whole 

 process of food gathering has a strongly marked mechanical 

 character that makes it much less successful as a means of 

 getting all the food within reach than the operations carried out 

 by the anthozoan tentacle (Torrey, '04 a, p. 401). This lack of 

 close adjustment, that has been noticed in the tentacles of 

 Tubularia (Pearse, '06, p. 403) as well as in those of Corymorpha, 

 runs through all the reactions of Corymorpha as compared with 

 those of the anthozoan polyps. 



Notwithstanding the general inefficiency of the responses of 

 Corymorpha, this polyp contains among its muscles about the 

 same array of types as are found in the actinians. Some 

 muscles, like the circular muscle of the stalk, are apparently quite 

 without nervous connections and respond to direct stimulation; 

 others, like the circular muscle of the proboscis, probably usually 

 respond to direct stimulation though they may be influenced 

 by nervous impulses; and finally muscles, like the longitudinal 



