PLATE 13. 

 Bacterium pestis. Lehm. and Neurn. 



I. Streak culture (ascites-glycerin-agar), three days 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 f 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. 

 < 60. Superficial colonies. They correspond to the dew- 

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

 Younger, (b) older colonies. 



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



(a) Ordinary agar ~\ 



(b) Glycerin-agar 5- 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 



VI). 



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. 

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

 Stained with fuchsin. 



