E. W. BERGER ON THE CUBOMEDUS. 27 
due solely to the restlessness of the animal after the operation. Later 
it swam actively for by far the most part on the surface only, which 
points to the truth of the preceding statement. 
It showed no reaction to light. A coat placed over the jar was 
removed, when it was found to be on the surface and it remained 
there. This was twice repeated. I noticed specially that on pushing 
the bell above the surface of the water it at once turned and went 
deeper as the normal animal does. Finally, given another trial with 
removing the coat from the jar, it went to the bottom as the normal 
animal usually does. After this, when next seen, it was keeping to 
the bottom. [This experiment was repeated on another occasion with 
almost identical results, no loss of sense-perception being noticeable. ] 
Sometimes it seemed as if access of light at removing the coat 
acted as a stimulus to one or more of those that were quiescent on 
the bottom. This was noticed again on the following day. 
11. Two more were operated upon. These did not stand the 
operation well and stayed on the bottom, one swimming, while eight 
hours later one was in better condition (pulsating) than two left in 
the same dish for comparison. 
12. a. Three clubs were cut off leaving only the stalks. A 
temporary paralysis of the power to swim was the immediate effect. 
Later it partially recovered this power. The proboscis, which was 
previously quiet, now showed convulsive twitchings and movements. 
It continued for some time to move to one side and then the other 
(after short pauses of varied length) as if to grasp some object. 
The lips of the proboscis were also moving and at times expanding. 
Often the movements were towards the side on which the club was 
uninjured. 
b. The fourth club was next removed, <A temporary paralysis 
as before resulted, followed by a quick recovery of pulsation; but 
the animal was now much weakened. The movement of the 
proboscis continued—shortening, lips expanding, moving to this side 
or that. The pulsations of the bell were kept up even when _ too 
weak to swim. 
c. The sensory niches of this same animal were treated with 2.5 
per cent. acetic acid by means of a pipette. The stalks of all four 
clubs showed white. Pulsations ceased. The velarium showed feeble 
local contractions. The movements of the proboscis and suspensoria 
drawing down the stomach continued. Upon stirring the animal it 
