42 ZOOTHAMNIUM SPIRALE. 



ciliated Infusoria. The first one that I saw attached 

 I conceived to be a remarkably large bell, with its 

 mouth directed towards me, but the cilia with which 

 it appeared to be fringed were unusually large and 

 distinct. The movements of these appendages being 

 comparatively slow, it was most interesting to watch 

 them as they successively bent inwards and rose 

 again, like the steady swell of a tidal wave, or an 

 eccentric movement in some piece of machinery, 

 making a revolution about twice in a second, and in 

 the opposite direction to the hands of a clock. Sud- 

 denly the tree contracted, when, to my surprise, I 

 observed the bell, which not an instant before ap- 

 peared attached, now floating freely in the water, its 

 ciliary movements not being in the least interrupted. 

 Presently, however, they became brisker, the bell 

 turned over on its side, and, ere the tree had again 

 expanded, darted out of view, not. however, before I 

 had remarked that it was not a bell, but a sphere 

 flattened on one side, and having its circular ring of 

 cilia on the flat side, with only a slight depression in 

 the middle of it. There also appeared to be a small 

 granular nucleus immediately above this depression, 

 the rest of the body being perfectly transparent. I 

 afterwards saw several others attached to the tree, 

 each seated about the centre of a branch ; but none 

 of these were so fully developed. They were like 

 little transparent button mushrooms, and had all 

 more or less of a nucleus on the side by which they 



