360 ORGANIC GROWTH sec. 



independence in the activity of the two portions still existed. 

 On the other hand, if I touched a in the same wav, the 

 movement was no longer interrupted in this portion only, but 

 in botli a and h. It follows that the connection was almost 

 completely re-established. Three hours before it had still been 

 possible to interrupt the movement in a alone by a touch. 



Towards evening I divided the other seven rows of 

 swimming-plates as well, by making a shallow circular cut 

 round the whole body, from the cut already made. The 

 movement of the plates thereupon ceased all over the animal, 

 but recommenced very soon on the row previously operated 

 on, and after some time on the oral segments of all the rows, 

 last of all on the oral portions of the rows — but in these it 

 was irregular and not very vigorous. 



On the following day at 10 A.M. I found all the plates of 

 the animal operated on in active motion. But a complete 

 connection between the oral and aboral portions of the 

 rows was not everywhere established. In four of the rows 

 the waves seemed to be continued from one portion into the 

 other, they were propagated apparently continuously across 

 the cut ; but in the other four they evidently originated in 

 each portion independently, only occasionally they had in two 

 of these the appearance of continuity — however, in the latter 

 it was still possible to interrupt the movement in the lower 

 portions while it continued in the upper, but the converse 

 was not possible. 



Experiment B I have made with different variations on 

 numerous other Beroes, and with results essentially the same: 

 gradual recovery of the movement and of its continuity in the 

 several rows always took place, until the movement went on 

 in the animal after the operation in the same way as before. 



But the following phenomenon also was repeatedly ob- 

 served : when a circular cut was made in a Beroe in the 

 manner above described some centimetres below the aboral 



