206 Herbert W. Rand 
siderable contraction of the tentacle. But, so long as irritation 
of the distal end of the tentacle was avoided, the contraction did 
not exceed two-thirds of the original dimensions. A few minutes 
after it had been tied onto the tube the tentacle began to make 
spontaneous movements, alternately extending slightly and then 
contracting again. It also bent or waved from side to side some- 
what as normal tentacles often do. “These movements, however, 
involved only comparatively slight changes in the degree of con- 
traction. The tentacle, under these conditions, never fully ex- 
tended to its original dimensions. ‘Then water was dropped into 
the funnel until it stood in the tube at a height of about twenty-five 
millimeters above the surface of the water in the bowl. Under 
this internal pressure the tentacle swelled out somewhat and 
assumed the general form of a normal tentacle, but its dimensions 
remained about one-half its original dimensions when extended. 
Further, the spontaneous movements ceased and the tentacle 
became perfectly rigid. It gave not the slightest response to 
tactile stimulation. If struck violently and pushed from side to 
side it merely sprang back to its original position just as any inani- 
mate thing of like form and texture, and similarly under internal 
pressure, would have done. ‘The pressure was increased up to 
thirty-five millimeters without in any way changing the behavior 
of the tentacle. (In another case, the tentacle contracted under 
twenty-five millimeters pressure, raising the column of water inthe 
tube.) At this point in the experiment the distal half of the ten- 
tacle was clipped off. Instantly the proximal half collapsed and 
contracted close to the end of the tube. After the lapse of about 
half an hour the contracted stump of tentacle occasionally showed 
a slight tendency to extend. Thereupon, at one of these moments 
of extension, a gentle internal pressure was produced by raising 
the water in the tube to a height of 1o mm. The piece of tentacle 
at once swelled out conspicuously and attained approximately 
the dimensions which it had before the distal half was cut away. 
But, when thus expanded, its recently cut distal end was found to 
be practically closed. ‘The appearance of a tentacle under these 
conditions is represented in Fig. 8. At the tapering tip of the 
tentacle appeared to be a small circular pore. Yet this pore must 
