PLATE 58.

Corynebacterium diphtheria. (Klebs, Löffler.) L. and N.

Corynebacterium pseudodiphtheriticum. (HofmannWellenhof.) Lehm. and Neum.

Corynebacterium xerosis. (Kuschbert, Neisser.) Lehm. and Neum.

I. Coryneb. diphtheria. Glycerin-agar streak culture, three days at 37°. Luxuriant growth; culture moist.

II. Coryneb. diphtheria. Glycerin-agar streak culture, three days at 37°. Delicate growth.

III. Coryneb. pseudodiphtherit. Glycerin-agar streak culture, three days at 37°. Luxuriant growth, culture moist.

IV. Coryneb. xerosis. Glycerin-agar streak culture, three days

at 37°. Delicate growth; growth dry and dull.

V. Coryneb. pseudodiphtherit. Glycerin-agar stab culture. Surface growth, ten days at 37°. The culture is reproduced on account of its atypical brown color.

VI. Coryneb. diphtheria. Gelatin stab culture. Surface growth, ten days at 22°. The color fluctuates from white to dirty yellowish.

VII. Coryneb. diphtheriæ:

Natural size.

(a) Glycerin-agar plate. Colonies upon the surface, three days at 37°. Luxuriant growth. The same culture as I.

(b) Glycerin-agar plate. Colonies upon the surface, three days at 37°. Delicate growth. The same culture as II.

VIII a. Coryneb. pseudodiphtherit. Glycerin-agar plate. Colonies lying upon the surface, three days at 37°. Natural size. Luxuriant growth. Answers to culture III.

VIII b. Coryneb. xerosis. Glycerin-agar plate. Colonies lying upon the surface, three days at 37°. Natural size. Dry, dull growth. Answers to culture IV.

VIII c. Coryneb. xerosis. Glycerin-agar plate. Colonies lying upon the surface, three days at 37°. Natural size. Delicate growth. Sometimes it may be still more delicate.

IX. Coryneb. diphtheria. Potato culture, ten days at 22°. The growth is typical, like a delicate veil, which in many places leaves no trace on the potato.

X. Coryneb. pseudodiphtherit. Potato culture, ten days at 22°. The growth is sharply outlined, white to dirty yellowish,