ORDER INFUSORIA HOMOGENEA. 521 
round the whole body; KERONA, when there are some large 
ones, representing a sort of horns; HIMANTOPUS, when 
these pretended horns are elongated into a kind of filament. 
The second tribe 
Presents those which have no visible external organs, unless 
we consider a tail as such. 
CERCARIA, Miill., 
Have, in fact, their oval body terminated by a filament. To 
this genus belong, among others, the animalculz, which are 
observed in the semen of different animals, and on which so 
many fantastic hypotheses have been founded. 
When this filament is forked, as sometimes happens, M. de 
Lamarck names these animals 'TURCOCERCA. 
VIBRIO, Miill., 
Have the body slender, and round, like the little end of a 
thread. 
It is to this genus that belong the pretended eels in glue 
and vinegar. Vib. glutinis et aceti. These last often dis- 
tinguishable by the naked eye. It is asserted that they 
change skin, that they have sexes, produce living young in 
summer, and eggs in autumn. The frost does not destroy 
them. The first appear in the glue or paste of diluted flour. 
ENCHELIS, Miill., 
Have the body oblong, softer, less defined than that of vibrio. 
CYCLIDIUM have it flat and oval; PARAMECIUM, flat 
and oblong; KoLpopa, flat and sinuous; GONIUM, flat and 
angular; BursartiA, hollow like a sac. 
The most singular of all are 
PROTEUS, L. 
No determined form can be assigned to them; their figure 
