INFUSORIA. 471 



bodies are distinct!}'' severed. When separated, tliey 

 retain the round form for some time. 



When a drop of water is examined between two 

 plates of glass, it is amusing to observe the numbers 

 that congregate in the sinuosities left by the gradual 

 drying of the fluid. This probably becomes unfit for 

 respiration, for the motion of the cilia becomes more 

 and more languid, and the creatures die before the 

 water is dry. They not only die but vanish, so that 

 where there were scores, so close that in moving they 

 indented each other's sides and craAvled over one 

 another — if we look away for a few minutes, and again 

 look, we see nothing but a few loose granules. This 

 puzzled me, till I watched some dying, and I found 

 that each one burst and as it were dissolved. The 

 cilia moved up to the very last moment, especially the 

 strong ones in front, until, from some point in the out- 

 line, the edge became invisible, and immediately the 

 animal became shapeless, and from the part which had 

 dissolved the interior parts seemed to escape, or rather 

 the skin, so to speak, seemed to dissolve, leaving only 

 the loose viscera. From the midst of these then pressed, 

 as if by the force of an elastic fluid within, several 

 vesicles of a pearly appearance, varying in number and 

 size, and then the whole became evanescent. 



You will have observed that the admixture of car- 

 mine to the water, while the animalcules were active, 

 bIiows the direction of the ciliary motion with great 

 distinctness. The particles form two vortices, one on 

 each side of the front, which meet in the centre in a 

 strong current, and pass oflf behind the m( uth on each 

 side. We do not perceive that any of them swallow 



