204 Herbert W. Rand 
assumed a more smoothly cylindrical form. The distal opening 
of the proximal piece, as well as the proximal opening of the distal 
piece, was at first slit-like in form and remained so for several 
minutes, apparently as a persistent result of the pressing together 
of opposite edges of the wall in the act of cutting. The cut edges 
were, from the first, slightly bent inward. 
In some preliminary experiments with detached tentacles I 
had found that, when a tentacle lay upon the bottom of the aqua- 
rium in a collapsed and contracted condition, a very slight current 
of water directed by means of a pipette into the open end of 
it often resulted in a partial extension and inflation of the ten- 
tacle, and this effect might endure for several seconds. It often 
appeared as if the expansion were due not entirely to the direct 
mechanical effects of the slight pressure, but, at least in part to 
a relaxation of the tissues of the walls, induced perhaps by the 
stimulus of the pressure. Inthe present experiment, about eight 
minutes after the second cutting I directed a gentle current of 
water from a pipette against the proximal opening of the proximal 
piece with the result that the piece became plump and smooth 
and extended noticeably in length. In this slightly extended 
condition it became apparent that there was a definite circular 
region of contraction around the distal opening which then ap- 
peared as a round pore. In a few seconds the piece contracted 
again. In so doing, the distal hole enlarged markedly, as if by 
a relaxing of circular fibers, and, losing its circular outline, became 
irregular with some approach toward its previous slit-like form. 
Sixteen minutes after the second cutting this injecting operation 
was repeated. ‘This time the result of the slight internal pressure 
was a very marked expansion in diameter with only slight change 
in length. The piece swelled out to a bulb-shaped form, while 
its distal region, sharply contracted, formed the characteristic 
cylindrical nipple traversed by a small circular opening. Fig. 5 
shows the appearance of the piece at this moment of expansion. 
The proximal cut end, although it shows a certain amount of 
contraction, is yet wide open. 
I then turned my attention to the distal portion of the severed 
tentacle. Twenty minutes after the original operation I cut a 
