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 



