194 



INFECTIVE DISEASES. 



This has also been observed in sections of the internal organs of a 

 rabbit which had been inoculated with the anthrax bacillus and had 

 died of septicaemia the following morning. 



Test-tube Cultivations in Nutrient Agar-agar. Cultivated upon a 



FIG. 94. COLONIES OF BACILLUS ANTHRACIS, x 80 (FLUGGE). 

 a, after 24 hours ; I, after 48 hours. 



sloping surface of nutrient agar-agar a viscous snow-white layer is 

 developed, but without access of air no cultivation can be obtained, 

 the bacilli being aerobic. This can be demonstrated by completely 



embedding a piece of lung or spleen 

 pulp containing bacilli, in nutrient 

 agar-agar (p. 22). 



Potato - cultivations. In about 

 thirty-six to forty-eight hours a creamy- 

 white or very faintly yellowish layer 

 forms over the inoculated surface, 

 usually with a translucent edge, and 

 sometimes a strong, penetrating odour 

 of sour milk. 



Plate-cultivations. From the spleen 

 or blood of the heart cultivations may 

 be made in nutrient gelatine on plates. 

 The colonies develop in about two days, according to the temperature 

 of the room. They appear to the naked eye as little white spots 



FIG. 95. IMPRESSION-PREPARA- 

 TION OF A COLONY, X 70. 



