Microscopical Essays, 



433 



Of the Vorticell^e. 



We now come to another divifion of thefe animals, to which 

 later writers have given the name of vorticellas, which we {hall 

 therefore adopt, as we think it behoves every man to maintain 

 that order in fcientific arrangement which is not inconfiftent with 

 truth, except he can produce another arrangement more ex- 

 preffive of the nature of the objects it is defigned to difcriminate. 



The variety that may be obferved in thefe minute animals, con- 

 firms a principle, which the more it is looked into, the more it 

 will be found to accord with the general operations in nature, 

 namely, that there is always a pre-exiftent principle of life 

 necefTary to the organization both of animals and vegetables ; 

 that the alimentary and other particles which are added to, or ap- 

 parently belong to them, produce nothing of themfelves, they are 

 incapable of forming the leafl fibre, but they are able to become 

 eonftituent parts of one organical whole, and the inftruments 

 whereby the forming principle is manifefled, and rendered capa- 

 ble of acting upon certain orders of creatures. 



VORTICELLA. 



Animal, calyce vafculofo ; ore contractili ciliato, terminal! 

 flirps fixa. 



A fmall animal, with a vafcular cup ; the mouth is at one end 

 ciliated, and capable of being contracted, the Item fixed. 



VORTI- 



