58 NATURAL HISTORY 



GENUS V. 



VIBRIO. 



The extensive range of this genus^ in regard to the 

 structure, form, and size of the different species, offers 

 great variety to the observer. The complex organiza- 

 tion of the Anguillula, the singular form of the spirillum^ 

 and the diverting manners of the olar, will afford the mi- 

 croscopist considerable information and amusement; 

 while the investigation of the division, Bacillaria, on 

 the very verge of the vegetable kingdom, will require 

 his patient attention, and strain the powers of his mi- 

 croscope to the utmost. 



Regarding this genus in a scientific point of view, it is 

 the most vague and indefinite in MuUer's system, either 

 as regards their external characters, or internal structure: 

 it includes animalcules both membraneous and crusta- 

 ceous ; some as slight as a thread, others whose breadth 

 nearly equals their length ; some whose organization is 

 so complete that modern naturalists have entirely ex- 

 cluded them from the Phytozoa ; and others, which are 

 with difficulty distinguished from vegetables. To di- 

 minish somewhat these incongruities, without rendering 

 the arrangement complex, I have separated them into 

 three divisions. The first is the simplest, and requires a 

 magnifying power of from 200 to 500 times to examine 



