Micrococcus tetragenus. Koch. Gaffky.
I. Agar streak culture, five days at 37°.

II. Gelatin stab culture, ten days at 22°. Stab canal. Characteristic nail-head form.

III. Gelatin stab culture, ten days at 22°; surface growth. In the reproduction the color has turned out brown, but should be white.

IV. Agar stab culture, six days at 37°. Surface growth.

V. Agar stab culture, six days at 37°. The growth along the stab is not always so luxuriant.

VI. Agar plate, five days at 37o. Natural size.

VII. Gelatin plate, eight days at 22°. The colonies are naturally pure white. Natural size.

VIII. Gelatin plate, eight days at 22o. X 60. The larger colony is superficial; the smaller, deep.

IX. Microscopic preparation. From a two-days’-old agar culture. X 800. There are not always found tetrads alone, often also single cocci.

X. Potato culture, seven days at 37o.

XI. Microscopic picture. Tetrads before, during, and after division; highly magnified.

Micrococcus pyogenes a aureus. (Rosenbach.) Lehm.

and Neum. (Staphylococcus aureus Ros.) I. Gelatin stab culture, six days at 22o. II. Agar streak culture, five days at 22o. III. Agar stab culture, five days at 22°. Stab canal. IV. Agar stab culture, five days at 22°; surface growth.

V. Agar plate culture, six days at 22°, natural size. Superficial and deep colonies. VI. Agar plate, six days at 22° X 60. Small super

. x ficial colony.

VII. Gelatin plate, four days at 22°, natural size. Superficial and deep colonies.

VIII. Gelatin plate, four days at 22° X 60. Superficial and deep colonies.

IX. Potato culture, six days at 22o.

X. Microscopic preparation. X 1000. From an agar culture, two days old, at 22o.

XI. Microscopic preparation. Single cocci, before, during, and after division. X 1500.