TUBULAR AND CELLULAR POLYPI. 175 



five flows occupied fifteen minutes and a half, — the same 

 average time being spent in the ebb as in the flow. The 

 longest continued stream was two minutes and a quarter ; the 

 longest suspension, half a minute. When the connexion of a 

 plume with the root was interrupted by bending its stem, the 

 stream running down the middle was observed to continue its 

 flow up one of the lower and stronger lateral branches, and 

 then to return down that branch, and up the main stem, — the 

 course of the current in most of the other side branches being 

 still the same as in the middle one. On a stem being cut off 

 below the commencement of the side branches, a few seconds 

 passed before any thing exuded from the stump. A small 

 stream of particles then issued, followed by a flow of viscous 

 matter ; this stopped awhile, then went on again, but ceased 

 altogether in about five minutes. It hung like honey about 

 the end ; and on its gradually clearing away, the wound appeared 

 healed. The alternate currents in the axis of the soft matter 

 were seen in all the Sertularice that were examined, and appear 

 to be an essential character of this family." 



Sertularia setacea. " From its transparency, and the 

 smaller number of its moving particles, their individual qui- 

 vering motions, and the course of its currents, were more 

 conspicuous than in the former species. The stream some- 

 times extended only to the pulp below the septum, and some- 

 times mounted into the stomach ; and in whichever part it 

 terminated, agitation took place there on the ceasing of the 

 upward flow. The soft part within the branches, which 

 adhered generally to one side of the tube, had the look of a 

 slimy matter, inclining to granular, and held together by 

 greater tenacity at its outside. Nothing like muscular motion 

 was seen in the pulp of this or any other species. As a little 

 globular animalcule was driving rapidly past one of the 

 expanded polypi, it instantaneously seized it, and brought it to 

 its mouth by contracting its arms. They gradually opened 

 again, except one, that remained awhile doubled with its end 

 on the animalcule. The mouth, indistinctly, seemed filled with 

 hairs or tentacula, that closed over the prey ; and after a few 

 seconds, it was carried slowly down, in the manner of the 

 ActinicB, the mouth contracting and the neck enlarging into 

 the stomach : here it was uncertainly seen, and soon dis- 

 appeared. Agitation of particles in the stomach followed the 



