PATHOGENIC BACTERIA. 



95 



or hair, if looked at under high power, being composed of bac- 

 teria in line. 



Stab Cultures. A white growth with thorn-like processes along 

 the needle-track ; later on, gelatine liquefied, and flaky masses 

 at the bottom. 



Potato. A dry creamy layer, and when placed in brood-oven, 

 rich in spores. 



Varieties. Asporogenic. By cultivation in gelatine, contain- 

 ing 1 to 1000 ac. carbolic, a variety develop that cannot produce 

 spores. Also involution forms, differing from the usual type. 



FIG. 48. 



Anthrax bacilli in human blood (fuchsin staining), Zeiss 1-12 oil immersion. 

 No. 4 ocular taken from Vierordt. 



Staining. They readily take all the aniline dyes with the 

 ordinary methods. To bring out the cup-shaped concave ex- 

 tremities, a very weak watery solution of methylin blue is best. 



Spores are stained by the usual method. When several bacilli 

 are joined together, the place of their joining looks like a spore 

 because of the hollowed ends. The double staining will develop 

 the difference. 



Sections of tissue are stained according to the ordinary 

 methods, taking Grants method very nicely. 



Pathogenesis. When mice are inoculated with anthrax mate- 



