340 J. M. D. OLMSTED 



tion at the same time, while in a finger-bowl at any given moment 

 the majority of the tentacles wave freely in the water, two or 

 three are attached to the surface, and two or three have been 

 drawn down into the mouth. The animal never remains mo- 

 tionless, but continually moves about, first attaching its tenta- 

 cles, and then after they are detached, drawing them down into 

 the mouth as if to wipe off particles which might be attached to 

 them. These wiping movements appear to be feeding movements, 

 yet they occur even when no food seems to be present. For this 

 reason Becher ('07) considered them automatic. Quatrefages 

 ('42) found that his Synapta duvernea would swallow grains of 

 sand when they were brought to the mouth on the tentacles. 

 Under no circumstances was I able to see particles of any sort 

 transferred from the tentacles to the mouth, though in several 

 experiments carmine grains were caught upon them. 



When carmine powder is dropped on the tentacles, they are at 

 once drawn back out of sight into the mouth region, the whole 

 body contracts, and peristaltic waves pass from posterior to 

 anterior. The following observations on one specimen illustrate 

 this behavior. 



July 21. Specimen 4- Collected this morning. Length 4.5 cm. 



3.53 p.m. Animal on bottom of dish. Carmine suddenly squirted into mouth. 



Draws in tentacles. Shortens body. Three peristaltic waves. 



3.55 p.m. Defecates. Three more waves. Climbs to top of dish. 



3.57 p.m. Drops to bottom. Draws in tentacles. Climbs up. 



4.00 p.m> Several peristaltic waves. 



4.01 p.m. Drops to bottom. Two peristaltic waves. Climbs up again. 

 4.05 p.m. Defecates. 



4.08 p.m. More waves. Drops to bottom. 



This is in strong contrast to the ordinary behavior, for a Syn- 

 aptula usually remains at the top of the dish for some 10 or 

 15 minutes without dropping, and no peristaltic waves are to be 

 seen. 



If carmine in sea-water is quickly squirted into the mouth 

 while the tentacles are extended, the red grains appear later in 

 the intestine, and finally come out in the castings. In fourteen 

 animals, each about 6 cm. long, carmine appeared in the castings 

 after an interval averaging 20 hours, and varying from 18 hours 



