Bacterium coli (Escherich). L. and N.
I. Gelatin stab culture, ten days at 22o.

II. Gelatin streak culture, four days at 22o. 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°. Surface growth. VI. Agar plate, four days at 22°. X 60. Deep colo

" nies. Compare also Plate 14, VI. VII. Agar plate, four days at 22° X 60. Part of a

. x 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°. Natural size.

IX. Potato culture, five days at 22°. May also be paler or more deeply colored.

X. Bacteria with long flagella of Bacterium brassicæ acide. X 1000. Stained according to Löffler.

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

XII. Bacteria with one flagellum, rarely two flagella, of Bact. coli 3 unipolaris. X 1000. Stained according to

B Löffler.

1.

II.