202 Herbert W. Rand 
incision into the side wall of a tentacle without completely sever- 
ing any part of it. With the tips of the scissors a cut was made 
extending one-fourth or one-third the distance around the cir- 
cumference of a large tentacle of Condylactis in a plane transverse 
to the axis of the tentacle and usually somewhere near the middle 
of its length. Tentacles injured in this way collapsed and con- 
tracted in the usual manner. After a period which varied from 
a few minutes to the greater part of an hour the tentacle again 
became extended and was then found to be sharply bent at the 
region of injury, the cut place being on the concave side of the 
bend. The bend was so abrupt that the injury itself was com- 
pletely hidden from view. I found it possible, however, by very 
gentle manipulation of the tentacle, to unbend it enough so that 
I could see the wounded place. By this means I was able to deter- 
mine that the original slit had been contracted to a small circular 
pore. In the persistent sharply bent condition of the tentacle 
there was probably no open passage through this pore. ‘The tissue 
immediately around the edge of the pore was white and very 
opaque, these qualities shading off gradually into the yellowish 
translucency of the tissue more remote from the injury. This 
whitish zone corresponded in extent to the contracted region of the 
tentacle at the bend. Furthermore, the degree of whitishness and 
opacity was in proportion to the amount of contraction. The 
injury lay at the exact center of the zone of contraction, which 
was responsible for the bending of the tentacle. The conditions 
which have just been described persisted for two or three days, but 
the size of the pore diminished all the time. Fig. 4 shows the 
appearance of a tentacle three days after an injury of this kind was 
inflicted. ‘The pore, which could be seen by gently straightening 
out the bend, was not larger than the point of a common pin. 
After another day or two (four or five in all) the pore was com- 
pletely closed and the tentacle began to straighten out. The 
unbending is very gradual, requiring several days. The whitish 
appearance at the concave surface of the bend persists so long as 
the bend is conspicuous, and gradually fades away as the tentacle 
straightens out. But even after the tentacle is well unbent a 
small white spot marks for a time the point where the pore closed. 
