CLASSIFICATION OF DAIRY BACTERIA. 187 
Gelatine colony.—A round, thick, smooth, or contoured, auriculate colony, of 
agray color. On ditmwus gelatine a large surface colony is produced, strongly 
acid, and with a gas bubble. Resembles B. dactis aerogenes. In some cultures 
it is thinner and of the coli type. 
Gelatine stab.—A filiform growth, and an umbonate surface, with a bluish 
sheen over the surface. 
Agar streak.—Not luxuriant, linear, raised, smooth, gray. 
Fermentation tubes.—Acidity, gas, and closed arm growth in all three sugar 
bouillons. 
Bouillon.—A sediment, decided turbidity, and a flocculent pellicle. 
Milk.—Rendered acid and curdled at 37°. No digestion, but a prominent 
odor. 
Potato,—Moderately luxuriant, thin, spreading, gray. 
Grows better at 20° than at 37° Facultative anaerobic. 
Variety A differs from the above in the following points: 
Variety A. Size, ux .5u. Flagellum very long. Gelatine stab, spreads 
from needle track below surface. Agar, luxuriant. Milk, curdled. 
Variety B. Size, 1.24x .5u, Gelatine colony, thin, transparent. Not acid 
on litmus gelatine. No acidity nor gas in lactose or saccharose, but showing 
closed arm growth. Potato, growth thin, cream-white. 
These organisms are in nearly every respect identical with B. coli communis, 
except that they have one flagellum instead of many. This flagellum is very 
long and characteristic. 
CLASSIFICATION OF DAIRY BACTERIA. 
Bacteria that are spherical in form, Coccaceae., 
Bacteria that are rod-shaped, Bacilliaceae. 
Coccaceae. 
Coccus forms that do not liquefy gelatine, 108, 188 
Coccus forms that liquefy gelatine, II7, 189 
Sarcina type, 124 
Bacilliaceae. 
Non-flagellate rods (Bacterium), I. 
Flagellate rods (Bacillus) II. 
‘Bacteria and Bacilli which produce acid and gas, - 182 
I. Bacteria that liquefy gelatine, 136, I90 
Bacteria that do not liquefy gelatine, 125, 189 
II. Bacilli with flagella over the whole body (Peritrichic), 164 
Bacilli with a single polar flagellum (Monotrichic), 150, 191 
Bacilli with a tuft of flagellaat theend (Lophotrichic), 159,191 
