PLATE 1.

Streptococcus pyogenes. Rosenbach.

I. Agar streak culture, ten days at 37°.

II. Gelatin stab culture, six days at 22°. So vigorous

a growth does not often occur.

III. Agar stab culture, six days at 37°.

IV. Agar stab culture, six days at 37°. V. Gelatin plate, six days at 22°. VI. Gelatin plate, six days at 22°. abnormal form with irregular borders. are superficial; the smaller, deep.

Stab canal.
Surface growth.

X 70. Somewhat
The larger colonies

X 70. Common

VII. Gelatin plate, six days at 22°. form. The upper, superficial; the lower, deep.

VIII. Agar plate, eight days at 37°. X 50. Larger colony superficial; smaller colonies, deep.

IX. Microscopic preparation from a two days' bouillon culture at 37°. 700. The individual cocci are usually

more regularly round.

X. Microscopic preparation from a two days' agar culture. Shorter chains. X 1000.

XI. Microscopic preparation, designated Streptococcus conglomeratus. Smear preparation from the blood of the spleen from a case of scarlatina. Copied from Kurth (Kaiserl. Gesundheitsamt., Bd. vII, cfr. xv, 6 and 8).

XII. Chains of streptococci, before and during division. Highly magnified.

PLATE 2.

Streptococcus lanceolatus. Gamaleia. (Diplococcus pneumoniæ A. Fränkel.) (Pneumococcus.)

I. Gelatin stab culture, ten days at 22°.
II. Agar streak culture, four days at 37°.

III. Agar stab culture, four days at 37°. Stab canal. IV. Agar stab culture, four days at 37°. Surface growth.

V. Agar plate, three days at 37°. VI. Agar plate, three days at 37°. colony. The darker colony lies near the VII. Agar plate, three days at 37°. onies.

Natural size.

X 50. Superficial surface.

X 50. Deep col

VIII. Gelatin plate, eight days at 22°. The upper colony is superficial; the lower ones, deep.

IX. Smear preparation from pneumonic sputum. X 1000.

X. Pure culture from a three days' old agar plate. X 1000.

XI. Microscopic preparations: (a) Diplococci as single pairs and in chains. Highly magnified. (b) Diplococci surrounded by gelatinous capsules.