38 JOHNS HOPKINS UNIVEESITY MORPHOLOGICAL MONOGRAPHS. 



May 22nd. A and B are living as also the pieces of the margin 

 of A; all are giving spontaneous pulsations now and then at compar- 

 atively long intervals even A, with its margin removed. 



May 26th. Everything is still living. The one with the margin 

 cut (A) counted sixteen and nineteen pulsations per minute, though 

 this was not kept up all the time. 



June 2nd. A and B and pieces are still living and contracting 

 spontaneously. It is now two weeks, and they were thrown out eaten 

 through at the aboral end with little or no regeneration. 



47. The margin was cut off another one (C) and it was then 

 paralyzed. The margin contracted vigorously by itself. The margin 

 was next split, but a connection of about one-half an inch wide was left 

 between the two rings. Over this bridge the contractions passed 

 from the outer and inner ring. The inner ring did not originate 

 any contractions. Both rings were then cut near their connecting 

 bridge of tissue and the larger ring with the marginal bodies was 

 split longitudinally so as to separate the exumbral from the sub- 

 umbral portion. It was found that the contractions started only from 

 the subumbral portion while the exumbral portion did not contract 

 at all. 



June 5th. Five of the eight small pieces of C were not seen to 

 contract either to-day or yesterday. A slow rotary motion was 

 observed in some of the pieces suggesting ciliation, but no cilia or 

 currents pointing to ciliation were seen with a low power. C was 

 seen to pulsate spontaneously. Possibly it did yesterday but it was 

 not watched closely. A piece of the subumbral surface of C broken 

 off (not from the margin) was found to contract spontaneously. 



48. June 6th. In a fresh one (D) from Port Royal, the eight litho- 

 cysts of one side were removed in order to compare its movements 

 with an intact one. Coordination was apparently unaffected. 



June 9th. The margin of C is still pulsating vigorously. Parts 

 of the subumbrella broken loose from the strip pulsated by them- 

 selves now and then. Fifteen lithocysts were removed, leaving only 

 one at the end of the strip. It was found that with this single 

 ganglion (lithocyst) left, and originating most of the contractions, now 

 and then a contraction would originate at another part of the strip 

 where there was no ganglion. Three days later contractions 

 originated as often from other parts as from the ganglion. 



