Microscopical 



Essays. 



300. Vorticella Nafuta. Fig. 38, 39, Plate XXVI. 



Vorticella cylindracea, crateris medio mucrone prominente. 

 Cylindrical, with a prominent point in the middle of the cup. 



An animalculum that is invifible to the naked eye ; but when 

 it is armed with microscopic lenfes, it appears curioufly furnifhed 

 with a rotatory organ, which encompafles the middle of the 

 body. 



It is pellucid, cylindrical, of an unequal fize, the fore-part (a) 

 truncated and ciliated, and a triangular prominency (e) in the 

 middle of the aperture ; the hind-part obtufe, a point on each 

 fide of the middle of the body. This is the appearance of 

 this little creature when in motion ; but when the water is nearly 

 exhaled, fome further parts of its Itru&ure are rendered vifible ; 

 befides the rotatory organ in the anterior part, another is now 

 difcovered encompaffmg the middle of the body; the hairs of 

 this are in vehement motion. There are other fafcicles of moving 

 hairs to be difcovered at the fame time. The variegated 

 and quick motion of this apparatus (more particularly if the 

 animalculum is big with young, and moving at the fame time 

 within the mother,) fill the mind with amazement. 



30 u Vor- 



