129 



CLASS XIV. INFUSORIA. 



Remarks. Cuvier says, it is customary to placey 

 at the end of the animal kingdom, those minute be- 

 ings, which escape the natural eye, and which 

 were never distinguished, until after the micros- 

 cope had developed a kind of new world. They 

 generally present gelatinous bodies extremely sim- 

 ple. These may be arranged together with pro- 

 priety. But many animals are placed here, mere- 

 ly on account of their minuteness. Those of this 

 description will probably be removed from this 

 class, after farther investigation. 



Infusory animals are best examined under the 

 solar microscope. To prepare them ; steep iu 

 cold rain water almost any vegetable, for several 

 hours ; then expose this infusion for a day or two 

 to the sun's rays, in a situation to bring the tem- 

 perature to that of common river water in the sum- 

 mer months. If a drop of this is put upon a piece 

 of glass, or between two pieces, placed in the fo- 

 cus behind the lens of a solar microscope, the 

 animalcula w r ill soon appear on the screen. 



ORDER 1. ROTIFERA. 



Bodies oval, gelatinous ; having mouths, stom- 

 achs and intestines ; often having a kind of tail, 

 and two prominences upon the neck appear to 

 bear eyes, and organs are seen ichich appear to be 

 concerned in respiration. 



VORTICELLA, (whirler,) body contractile, nak- 

 ed, and furnished with ciliate, rotatory organs, In 

 nil waters, 



