37°. Bacterium pestis. Lehm. and Neum. I. Streak culture (ascites-glycerin-agar), three days at II. Streak culture (agar), forty-eight hours at 37°. (After a culture of Dr. Dieudonné, preserved with formalin.) The streak was made with the juice direct from a bubo. The transparent, dewdrop-like growth is characteristic. III. Stab culture (gelatin), six days at 22°. The growth consists of minute, waxy, markedly elevated colonies, which become confluent; also the same upon the gelatin plate (v, b). IV. Plate culture (gelatin), six days at 22°. X 60. (a) Deep colony; (b) superficial colony. V. Plate culture: (a) Glycerin-agar, three days at 37°. Natural size. Superficial colonies. (b) Gelatin, six days 'at 22°. Natural size. Superficial colonies. Compare what is said under Fig. III. VI. Plate culture (agar), forty-eight hours at 37°. X 60. Superficial colonies. They correspond to the dewdrop-like colony in the agar streak culture (11). (a) Younger, (b) older colonies. VII. Plate cultures, forty-eight hours at 37°. X 60. (a) Ordinary agar (b) Glycerin-agar (c) Ascites-glycerin-agar Superficial colonies. (d) Ascites-glycerin-agar, deep colony. The crumbly character of cultures after being cultivated in contrast to very fresh cultures is to be noted (compare VI). VIII. Microscopic preparation, three days at 37° on glycerin-agar. X 1000. Stained with fuchsin. Involution forms. IX. Microscopic preparation: Smear from the juice of a bubo. 1000. Stained with methylene-blue. (From a preparation of Dr. Dieudonné.) X. Microscopic preparation: (a) Ordinary agar, twenty-four hours at 37°. X 1000. Stained with fuchsin. (b) Ordinary bouillon, twenty-four hours at 37°. X 1000. PLATE 14. Bacterium acidi lactici. Hüppe. (Lactic Acid Bacillus.) I. Gelatin stab culture, five days at 22°. The stab canal in nature is somewhat whiter. II. Agar streak culture, five days at 22°. III. Agar stab culture, three days at 220. Stab canal. IV. Agar stab culture, three days at 22°. Surface growth. V. Agar plate, three days at 22°. Natural size. VI. Agar plate, three days at 22°. × 50. Upper colony superficial, lower colonies deep. Compare also Plate 18, VII. VII. Gelatin plate, two days at 22°. Natural size. VIII. Gelatin plate, two days at 22°. X 50. Upper colony superficial, lower colonies deep. The superficial colonies may vary very much. Compare also Plate 16, VIII, IX; Plate 17, I, II; Plate 19, IV, VII. IX. Microscopic preparation. Pure culture from an agar colony. X 800. X. Potato culture, six days at 22°. The air-bubbles on |