214 Herbert W. Rand 
These changes involve something different from muscle action. 
There is not the least evidence of production of new tissue. It 
is old tissue which finally closes the cut end—the same tissue 
which by virtue of its own muscular contraction had temporarily 
closed the end during the extension phases of che tentacle. 
Some readjustment of the tissue elements takes place with 
the result that a layer which originally, in absence of muscle 
contraction and in presence of internal pressure, possessed a 
cylindrical surface becomes changed so that under similar condi- 
tions of tension and pressure it possesses a spherical surface. 
The process of this readjustment is a gradual and slow one. Its 
first effects may be seen in the contracted stump or fragment of 
tentacle within a few minutes after the cutting. The cut edges 
begin to draw inward toward the axis of the tentacle so as to 
diminish the area of the opening, but so slowly that the change 
is imperceptible except as conditions at intervals of an hour or 
two are compared. ‘This slow and gradual reduction of the distal 
opening appears to be entirely independent of the muscular activi- 
ties which have been described above. The tentacle passes 
through its alternate phases of contraction and extension (extended 
most of the time, if not disturbed), the cut end during extension 
being virtually closed by means of the nipple, while during con- 
traction it may be more or less widely open, but less widely open 
the longer the time which has elapsed since the act of cutting. Event- 
ually, as a result of this rearrangement of the tissue elements, the 
cut end becomes structurally closed and, so far as muscular ten- 
sion 1s concerned, conditions in the tissue which closes the end are 
uniform with those elsewhere in the tentacle—that is, the closure 
of the end is no longer dependent upon special muscular contrac- 
tion in that region. In the attached tentacle the progress of these 
changes is obscured owing to the fact that the tentacle, if not 
stimulated, remains constantly extended with its cut end always 
closed by the nipple. Yet these readjustments just as surely 
take place there, as is shown by the gradual and complete disappear- 
ance of the nipple and of the zone of muscle contraction around 
it. During the progress of these changes the closure of the end 
depends less and less upon muscle contraction, and more upon 
fixed structural conditions. 
