PLATE 13. 

 Bacterium pestis. Lelim. and Neum. 



I. Streak culture (ascites-glvcerin-agar), three davs at 

 37°. 



II. Streak culture (agar), forty-eight hours at 37°. 

 (After a culture of Dr. Dieudonne, 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 ; (6) superficial colony. 



V. Plate culture: (a) Glycerin-agar, three days at 37°. 

 Natural size. Superficial colonies. (6) 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 dew- 

 drop-like colony in the agar streak culture (11). (a) 

 Younger, (6) older colonies. 



VII. Plate cultures, forty-eight hours at 37°. X 60. 



(a) Ordinary agar ~) 



(b) Glycerin-agar j- Superficial colonies. 



(c) Ascites-glycerin-agar ) 



(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 



VIII. Microscopic preparation, three days at 37° on glyc- 

 erin-agar. X 1000. Stained with fuchsin. Involution 

 forms. 



IX. Microscopic preparation: Smear from the juice of a 

 bubo. X 1000. Stained with methylene-blue. (From a 

 preparation of Dr. Dieudonne.) 



X. Microscopic preparation : (a) Ordinary agar, 

 twenty-four hours at 37°. X 1000. Stained with fuchsin. 

 (6) Ordinary bouillon, twenty-four hours at 37°. X 1000. 

 Stained with fuchsin. 



