THE VIBRIO. 41 



action), by which means the aeration of the tissue and 

 fluids is effected, the whole mass brought into contact 

 with fresh portions of water, and the colony of monads 

 transported from place to place; and thus supplies of 

 food are constantly obtained. 



III. The Vivmo, or Trembling Animalcule,(ipl. n } fig. 1). 

 Some extremely fine hair-like bodies are seen moving 

 near the Volvox; these are groups of the polygastria 

 termed Vibrio, of which several species are commonly 

 present in water containing other animalcules. But lit- 

 tle is known of their structure, in consequence of their 

 extreme minuteness; for each filiform body is not an 

 individual, but a series of many, united together in a 

 flexible chain, from imperfect spontaneous transverse 

 division. This chain is straight when motionless; and 

 locomotion is performed by successive rapid undulations, 

 (see pi. n, fig. 1). 



