E. W. BERGER ON THE CUBOMEDUS.E. 31 



attachment. The stomach and the proboscis gave vigorous contrac- 

 tions and tied themselves all up so that I could not cut off the 

 proboscis. 



The four pieces of the floor of the stomach left on the interradii 

 gave contractions nicely. The phacelli continued their squirming 

 movements. 



25. Cutting off the whole aboral end of the animal excites to 

 very rapid pulsations of the remaining part. The stream, as shown 

 by particles in the water, is apparently stronger out the aboral end 

 than past the velarium. 



It seems that I get no good evidence that the subumbrella is able 

 to contract of itself without connection with special nerve centers. 

 In the one case noted (Experiment 31) I could not be sure but that 

 the part that contracted was intimately associated with the suspen- 

 sorium or frenulum. 



26. A piece of the subumbrella cut off and having, so far as I 

 could determine, no connection with ganglia, frenula, or suspensoria, 

 gave contractions. Another piece was not seen to contract. 



A small piece of the subumbrella connected with a club can contract. 

 The proboscis can give contractions of itself when cut off with the 

 base of the stomach. Even a cut-off lip can twitch by itself. A 

 portion of the subumbrella by itself also showed twitchings. (See also 

 Experiments 18, 19, 25, 26, 29, 47, 49.) 



Pedalia, Velarium, Radial and Inter radial Ganglia. 27. The pedalia 

 with their tentacles were cut off at their bases to insure cutting out 

 the interradial ganglia. The animal could pulsate well enough, but 

 intermittently and without much progress (the velarium, of course, 

 being injured). Cutting one pedalium caused the others to contract. 



28. When the pedalia were cut off from one, the power of direct 

 motion was entirely gone. It swam in circles, turned summersaults, 

 changed its course continually, the oral end getting ahead of the aboral 

 end, or trying to do so. The whole power of balancing was gone. It 

 seemed excited by the operation and swam continually. [Repeated.] 



29. The pedalia can be made to contract inwards by stroking their 

 outer edge with a needle. This was noted last year and has been 

 seen several times this year. Their inner edge is not so sensitive. 



Touching a sensory club caused the pedalia to contract inwards in 

 two cases. 



