INFUSORIA. 415 



ward as well as forward, occasionally shooting round and 

 round in a circle, with many gyrations, much like the 

 pretty little polished bettles (Gyrinus) that play in mazy 

 dances on the surface of a pool. The two extremities 

 seem covered with minute pits or stipplings, but colour- 

 less ; the central part is occupied with yellowish granules 

 of different sizes. 



I once witnessed the dissolution of one of these animals 

 under peculiar circumstances. Two or three stems of 

 an aquatic plant had become crossed in the live-box so 

 as to form an area, into which the Stylonychia had 

 somehow introduced himself. There was just room for 

 him to move backward and forward without turning, 

 and the space was about three times his own length. 

 Within this narrow limit he impatiently continued 

 crawling to and fro, moving his uncini with great 

 rapidity, and showing their extreme flexibility ; for, as 

 he applied them now to the stem, now to the surface of 

 the glass, these whip-like uncini were sometimes bent 

 double. The so-called styles at the posterior extremity, 

 though less frequently used so, were yet occasionally 

 bent and applied to the surface as feet, so that they are 

 certainly not inflexible as supposed, nor do I see any 

 essential difference between them and the uncini. The 

 whole body was flexible, taking the form of any passage 

 or nook into which it was thrust, yet recovering its 

 elasticity immediately the pressure was removed. Its 

 proper form appeared to be convex above and concave 

 beneath, rather than flat. After having been thus 

 employed about half an hour under my observation, it 

 became still, moving only its cilia, when I left it a little 

 while, and on my return found that it was dissolved ; 

 the outline having entirely disappeared, and nothing 

 being left but the granules, and globular vesicles, that 

 had constituted its viscera, some of which still contained 

 the carmine which had been very perceptible in the 



