$50 l^FUSOR-Y WORMS. 



numbered a species of the genus called Trichoda, chiefly charac- 

 terized by being beset with hairs or filaments. The species I have 

 just mentioned is the Trichoda Sol ; so named from its presenting 

 the appearance of a sun, as generally expressed in engraving ; viz. 

 a globe or ball, beset on all sides with very long diverging rays, or 

 spines. This animalcule is of a remarkable inactive nature, affixing 

 itself to the stem of some small water plant, and occasionally mov- 

 ing at the rate of about a quarter of an inch in an hour. Its size 

 may be considered as gigantic, for one of the animalcular tribe, 

 being equal to that of a small pin's head. This animalcule may be 

 pulled or torn in pieces, by means of a pair of needles or other con- 

 venient instruments, and in the space of a single hour each piece will 

 be apparently complete, and perfectly globular like the original. It 

 prays on small Monoculi, particularly on a very small species called 

 by Linnaeus Monoculus Pediculus, hardly larger than a grain of 

 sand. The Trichoda Sol appears to have been first described by a 

 German author of the name of Eickhorn, and afterwards more fully 

 by Mailer. 



The genus called Volvox also presents one of the largest and most 

 curious of Animalcules, as well as one of the most beautiful, the chief 

 species, or Volvox Globator, often equalling the size of a pin's head. 

 In the advanced stale of spring, and again in autumn, it appears in 

 immense numbers in the clearer kind of stagnant waters. Its ge- 

 neral colour is green; but it sometimes is of a pale orange-colour. 

 Its motions are irregular, in all directions, and at the same time rol- 

 ling or spinning as if on an axis. When microscopically examined 

 it presents one of the most curious phenomena in natural history, 

 being always pregnant with several smaller animals of its own kind, 

 and these with others still smaller : the whole external surface is 

 covered with very numerous small tubercles ; which some have sup- 

 posed to act as a kind of fins, while others have supposed them to 

 be the valves of so many orifices which the creature can either open 

 or close at pleasure, in order to manage its various motions. When 

 groupes of these beautiful animalcules are viewed by the solar mi- 

 croscope, they strongly recal to the recollection of the spectator the 

 magnificent scene in Mr. Walker's Eidouranion, representing nume- 

 rous worlds revolving in various directions. 



In a genus called Vibrio, from its vibrating or serpentine form 

 and motion, we meet with the largest of all the animalcular tribe, 



