ESTrSOKIA. 451 



r)icscnce of this organ M-as a depression in one part of 

 the surface, somewhat hke the mouth of a closed Acti- 

 nia, where there was a slight but incessant working, 

 very much like the irrcgnU\r motion on the surface of 

 boiling water, in miniature ; tliere was also an indistinct 

 ciliary action at this part, not of rotation, nor of vibra- 

 tion, but a sort of waving. At tliis point I had occasion 

 to get np from the table, and though I was not away 

 more than a minute, on my return I observed a strong 

 constriction around the middle of the bodv. It was 

 transverse, for the depressed and ciliated mouth was at 

 a point exactly at light angles to the constriction. 

 From the depth to Avhich this latter extended in so few 

 minutes, I sujiposed the process of separation would be 

 very rapid; for 1 could very soon see a line of light all 

 across at intervals, and the two halves seemed to slide 

 freely on each other. Yet they remained long without 

 much apparent progress, or even change, except that 

 the anterior half at one time threw forth its neck a 

 short distance ; at this time it looked extremely like a 

 bird, bridling np its lithe neck and swelling bosom ; 

 while to make the resemblance perfect, it began to 

 imitate the action of a fowl picking np grain, bobbing 

 its head hither and thither; so curious aretheanaloiries 

 of nature ! Along the dividing line, there had appeared 

 very early in the posterior half, a distinct ciliary action ; 

 after a while (how, I do not exactly know) without the 

 general relation of position being changed, the mouth 

 of the anterior (which must now be called the old) 

 animal appeared on the side, and at the point corres- 

 pondent in the other, a similar ciliary wreath appeared, 

 while the action along the dividing line was no longer 

 Been. So that the division which was at first transverse 



