40 AGRICULTURAL AND INDUSTRIAL BACTERIOLOGY 



sence of oxygen, although they are not strictly anaerobic. 

 Included in this genus are many bacteria important in the 

 souring of milk, the formation of lactic acid in silage, sauer 

 kraut, etc. 



FIG. 26. HEMOPHILUS. FIG. 27. LACTOBACILLUS. 



VI. FAMILY SPIRILLACEAE 



The organisms that belong to this group are curved 

 rods. Two genera are included, namely, Vibrio and Spiril- 

 lum. 



Vibrio. This genus includes short curved rods, motile 

 by means of one, two or three polar flagella. Many are 

 intestinal parasites and some are capable of causing disease. 

 The most important organism is the Vibrio cholerae pro- 

 ducing Asiatic cholera in man. 



Spirillum. Organisms belonging to this group are 

 longer, spiral cells, with a tuft of relatively long flagella 

 at the tip. They are not uncommon in water, and partic- 



FIG. 28. VIBRIO. FIG. 29. SPIRILLUM. 



ularly in water that contains decaying organic matter. 

 None of the species are of very much economic importance. 



