HISTORICAL. 19 



The genus Bacterium comprises six species, — 

 B. termo, catenula, punctum, triloculare, or ariicula- 

 tum, already described by Ehrenberg and Dujar- 

 din, and B. putredinis and capitatum, new species 

 of M. Davaine, established, the first for a bacte- 

 rium producing rot in plants, the second for a spe- 

 cies, swollen at the extremity, observed in some 

 macerations. 



The genus Vibrio includes twelve species, — 

 V. lineola, tremulans, rugula, prolifer, serpens, 

 bacillus, synxanthus, and syncyanus of previous 

 authors and the V. lactic, butyric, and tartaric 

 right, discovered by M. Pasteur in these different 

 fermentations. 



In the genus Bacteridium, M. Davaine places 

 five new species, — the " Bacteridies charbonneuse, 

 intestinale, du levain, glair euse, et des infusions." 

 He includes also the ferment which, according to 

 M. Pasteur, occasions the " sickness of turned 

 wine." 



Finally, the genus Spirillum includes the spe- 

 cies S. undula, tenue, volutans of Ehrenberg, 8. 

 rufum and leucomcenum of Perty, and S. plieatile, 

 Duj. 



From this moment the history of the bacteria 

 enters upon a new phase. The labors of M. Pas- 

 teur upon the inferior organisms and their role in 

 fermentation, the researches of MM. Davaine and 

 Hallier upon the bacterium of charbon, and the 

 micrococci of contagious maladies, call the atten- 

 tion of chemists and of pathologists to these or- 



