Biological Studies on Corymorpha. 399 



base or the tip, on the oral, aboral or lateral surfaces. The re- 

 sponse is always a bend inward, never outward. In this respect 

 it differs from the tentacular responses in some anemones (Cri- 

 brina, Sagartia), where a tentacle commonly reacts to a slight 

 touch by bending sharply at and toward the point stimulated. 

 This reflex is clearly advantageous to the anemone, which it 

 enables, to a limited extent, actually to pursue its prey. It is 

 supplemented by another. As soon as the tentacle, which is 

 adhesive, seizes the stimulating object, it contracts, carrying its 

 capture to the mouth, over which it bends. Then, by means of 

 the cilia with which the tentacle is covered, the object, at least if 

 available for food, is swept off the end of the tentacle and dropped 

 upon the lips. 



While the general direction of the movement of the tentacles 

 does not vary, the intensity of the contraction varies with the 

 intensity of the stimulus. A touch or slight pinch produces a 

 waving of the tentacle toward the proboscis, though without 

 reaching it; and the tip of the tentacle is not directed toward the 

 mouth. A stronger stimulus may cause the tip to touch the distal 

 tentacles, may even cause the tentacle to coil against the proboscis. 



When the stimulus reaches a greater intensity, it may induce 

 simultaneous movements in several or all the proximal tentacles. 

 Before this point is reached, however, it is able to set up move- 

 ments in the distal tentacles and proboscis. If a proximal ten- 

 tacle contracts, an effect is often evident among the distal ten- 

 tacles, even though the proximal tentacle has not touched them. 

 This effect is manifested either by a simultaneous downward 

 movement or an indeterminate waving of all the tentacles, or by a 

 downward motion of a few nearest the tentacle stimulated. 



These movements of the distal tentacles may occur without any 

 apparent movement in the proboscis. If, however, the stimula- 

 tion of the proximal tentacle is increased (occasionally a very 

 slight stimulus is sufficient to produce the movement) the pro- 

 boscis also may bend, carrying the mouth and distal tentacles 

 toward the tentacle stimulated. This is a coordinated reflex of 

 the same purposive aspect as the movements of the proboscis of 

 the medusae Sarsia, Tiaropsts (Romanes, '77) and Carmarina 



