18 THE BACTERIA. 
vibrios with JLeptothrix. This opinion, which 
was not favorably received by the authors who 
adopted nearly all of the generic groups of Ehren- 
berg and Dujardin, is to-day accepted by many 
botanists, above all since the labors of Cohn. (See 
below: classification.) At all events, it is to M. 
Davaine (1859) that we are indebted for clearly 
pointing out that the vibrioniens are vegetables, 
nearly allied to the alge, and especially to the 
confervee. 
This same author, having observed some mo- 
tionless bacteria, thought it necessary to give 
this character great consideration, and to estab- 
lish a fourth group, the genus Bacteridium, which 
he added to the three others admitted by Dujar- 
din; but in this creation he was less happy than 
in his placing the vibrioniens among the vege- 
tables; for we shall see further on that this char- 
acter of mobility or of immobility is not absolute, 
and that it depends upon the age of the bacterium 
or upon certain conditions relating to the medium 
in which it is placed. 
The most recent complete exposition of the 
classification and of the ideas of M. Davaine is 
found in the “ Dictionnaire Encyclop. des Sci- 
ences Médicales,”’ art. Bactéries (1868). It may 
be summed up as follows: — 
Filaments straight ) Moving sponta-) Rigid. . BactTErium. 
or bent, but not neously.. . Flexible. Vusrio. 
in a spiral Motionless . . . . . BACTERIDIUM. 
Hilamiente Spital .)e 2.6 aj) me aepew a 4 CEIRL EL ee 
