For a few weeks I continually met with groups living as I have described, in what may be called amorphous cells, which were often so nearly like the surrounding water in refracting power, as to be discerned with some difficulty. No trace could be seen of divisions into separate cells, but they all appeared to live happily together in one room, and if one went up all went up, and if one went down all went down, as if their proceedings were regulated by a community of sensation or will. Another little curiosity was a transparent cup upon a slender stem, which stood upright like a wineglass, and supported on its mouth a transparent globe. By removing a leaf which prevented the stalk being traced to its termination, it was found to be a Vorticella, and after two hours the globe was partially drawn in, and reduced in size. Why the creature was engaged in blowing this bubble I do not know, and have not met with another instance of such conduct. CHAPTER XI. NOVEMBER. Characteristics of the Polyzoa--Details of structure according to Allman--Plumatella repens--Its great beauty under proper illumination--Its tentacles and their cilia--The mouth and its guard or epistome--Intestinal tube--How it swallowed a Rotifer, and what happened--Curiosities of digestion--Are the tentacles capable of Stinging?--Resting Eggs, or "Statoblasts"--Tube of Plumatella--Its muscular Fibres--Physiological importance of their structure. During the fag end of last month I observed some fragments of a new creature among some bits of Anacharis, from the Vale of Heath Pond, and searched for complete and intelligible specimens without effect. Luckily one evening a scientific neighbour, to whom I had given some of the plant for the sake of the beautiful _Stephanoceri_ which inhabited it, came in with a glass trough containing a little branch, to which adhered a dirty parchment-like ramifying tube, dotted here and there with brown oval masses, and having sundry open extremities, from which some polyp-shaped animals put forth long pearly tentacles margined with vibrating cilia, and making a lively current. The creatures presented an organization higher than that of polyps, for there was an evident _differentiation_ and complication of parts. They belonged to the _Polyzoa_ or _Bryozoa_,[21] a very important division of the _mollusca_. The _Polyzoa_ are chiefly marine, and the common "sea-mat," often erroneously treated as a _sea-weed_, is a well-known form. A species of another order often picked up on our coasts is the _Sertularia_, or Sea-Fir, composed of delicate branching stems of a horny-looking substance, which, under a pocket-lens, is found to contain an immense number of small cells inhabited by Polyps. It is instructive to compare the two and note how much more advanced in structure is the Polyzoon than the polyp.