30 JOHNS HOPKINS UNIVERSITY MORPHOLOGICAL MONOGRAPHS. 



so as to perfectly separate the sensory clubs and the pedalia. 

 Pulsations continued synchronously in all four sides not the 

 slightest evidence that one side contracted out of time with the 

 others. 



23. The eight cuts were made as in the preceding experiment 

 with no loss of coordination noted. When the cuts were carried up 

 to the base of the stomach, however, coordination ceased. The four 

 side pieces seemed to contract each in its own time. Only two sides 

 could be observed at one time, and they at any rate did not contract 

 synchronously. One side often gave- two contractions while the 

 other side rested or gave one. 



Yet, a little later, three of the sides at any rate showed a 

 pretty good coordination. The fourth was smaller and did not seem 

 to get into the game much it went more on its own schedule. 

 The four pieces were then cut apart and placed together under a 

 dissecting microscope. No coordination at all could be made out. 

 No evidence, therefore, of any definite rate of pulsation inherent in 

 the sensory clubs. 



Cutting the nerve causes the pedalia to forcibly contract inwards. 



Side, Subumbrella. 24. A whole side was cut out, the transverse 

 cut being above, the sensory organ so as to take off [leave off] the 

 radial ganglion also. This pulsated, or rather contracted, nicely. 

 The upper end had been cut just through the suspensorium. It 

 especially gave twitchings like the twitchings of the stomach. The 

 piece was then halved transversely, when the upper part containing 

 the portion of the suspensorium twitched as before while the lower 

 part was not seen to contract again. This was repeated with the same 

 result, except that a portion of the lower part gave a slight contraction 

 several times. The part that contracted was at the upper end of the 

 piece, i. e., nearest the suspensorium. The contractions were also more 

 longitudinal than transverse, as the regular contractions would be. 



The piece connected with the sensory clubs of course pulsated 

 nicely. Upon cutting off the sensory club from the stalk, pulsation 

 ceased, but twitching of the velarium continued. This was repeated 

 with the same effect. 



In the same animal, in cutting off the sides, the stomach was 

 left, the cut being through the gastric ostium. The floor of the 

 stomach was now cut off by cutting out the four interradial points of 



