Bacterium coli (Escherich). L. and N.

I. Gelatin stab culture, ten days at 22°.

II. Gelatin streak culture, four days at 22°. In nature is transparent, resembling mother-of-pearl in iridescence. Compare also Plate 16, vi.

III. Agar streak culture, four days at 22°. Compare also Plate 16, v.

IV. Agar stab culture, two days at 22°. Stab canal.
V. Agar stab culture, two days at 22°.

growth.

Surface

VI. Agar plate, four days at 22°. X 60. Deep colonies. Compare also Plate 14, vi.

VII. Agar plate, four days at 22°. X 60. Part of a superficial colony. May also occasionally present forms like the bacillus acidi lactici. Compare Plate 12, Iv; Plate 14, vi; Plate 17, vi.

VIII. Agar plate, three days at 22°.
IX. Potato culture, five days at

paler or more deeply colored.

Natural size.

22°.

May also be

X. Bacteria with long flagella of Bacterium brassica acidæ. X 1000. Stained according to Löffler.

XI. Bacterium of pigeon diphtheria surrounded by flagella. 1000. Stained according to Löffler.

XII. Bacteria with one flagellum, rarely two flagella, of Bact. coli & unipolaris. X 1000. Stained according to Löffler.

X.

XI.

XII.