446 



THE MICROSCOPE. 



rooted, as it were, to a single spot by its slender stalk ; its 

 Creator has foreseen the probable arrival of a period in its 

 existence when the power of locomotion would become 



Fig. 226. 



1, ? 3, Hydras in various stages of development. 4, A group of Stentor poly- 

 morphus, many-shaped Stentor. 5, Englenu, 6, Monads. 



necessary, and this necessity is provided for in a manner 

 calculated to excite our highest admiration. At the lower 

 extremity of the body of the animal, at the point of its 

 junction with the stalk, a new fringe of cilia is deve- 

 loped ; and when this is fully formed, the Vorticella quits 

 its stalk, and casts itself freely upon its world of waters. 

 The development of this locomotive fringe of cilia, and 

 the subsequent acquisition of the power of swimming by 

 the Vorticella, is generally connected with the propagation 

 of the species, which, in this and some of the allied genera, 

 presents a series of most curious and complicated phe- 

 nomena. 



