HISTORICAL. 15 
tranquilla, lamellula, pulvisculus, uva, which it 
is impossible to identify with the species at pres- 
ent recognized. The genus Vibrio “ vernis incon- 
spicuus, simplicissimus, teres, elongatus,” enclosing 
under thirty-five specific names, with the true 
bacteria, some organisms belonging to other 
classes of the animal and vegetable kingdoms. 
In the classification of the infusoria given by 
Bory de Saint-Vincent in the “ Encyclopédie 
Méthodique ” (1824) and afterwards in the “ Dic- 
tionaire Classique d’Histoire Naturelle” (1850) the 
bacteria are distributed in two different families 
of the microscopic gymnode, the monadaires and 
the vibrionides. Besides the monads, properly so 
called, of which the Monas termo has been pre- 
served by the greater part of the bacterologists, 
the monadaires include some veritable infusoria, 
which have no relation with the monads. It was 
the same with the vibrionides, of which the genera 
Vibrio and Mellanella included some beings very 
different in their organization. Indeed, beside 
some veritable vibrios, bacteria, and spirilla, 
constituting the genus Mellanella, Bory placed 
some nematoid worms, such as the Anguwillula 
of vinegar. 
With Ehrenberg (1838) and Dujardin (1841) 
the family of the vibrioniens was established upon 
characters more homogeneous, and their species 
upon distinctions truly scientific. But these two 
observers, followed in this by M. Davaine, deny 
completely the affinities of the elongated bacteria 
