I08 ESSENTIALS OF BACTERIOLOGY 



Varieties. Asporogenic. By cultivation in gelatin, contain- 

 ing i : 1000 phenol, a variety develops that cannot produce 

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



Staining. They readily take all the anilin dyes with the 

 ordinary methods. To bring out the cup-shaped concave 

 extremities, a very weak watery solution of methylene-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 Gram's method very nicely. 



Pathogenesis. When mice are inoculated with anthrax mate- 

 rial through a wound in the skin, they die in twenty-four hours 

 from an active septicemia, the point of inoculation remaining 

 unchanged. The following appearances then present them- 

 selves: 



Peritoneum. Covered with a gelatinous exudate. 



Spleen. Very much swollen, dark red, and friable. 



Liver. Parenchymatous degeneration. 



Blood. Dark red. The bacilli are found wherever the capil- 

 laries are spread out, in the spleen, liver, intestinal villi, and 

 glomeruli of kidney, and in the blood itself. Only when the 

 capillaries burst are they found in the tubules of the kidney. 



Mode of Entrance. The bacilli can be inhaled, and then a 

 pneumonia is caused, the pulmonary cells containing the bacilli ; 

 when the spores are inhaled, a general infection occurs. 



Feeding. The cattle graze upon the meadows, where the 

 blood of anthrax animals has flowed and become dried, the 

 spores remaining, which then mix with the grass and so enter 

 the alimentary tract; here they then cause the intestinal form 

 of the disease, ulcerating through the villi. 



Local Infection. In man usually only a local action occurs; by 

 reason of his occupation wool-sorter, cattle-driver, etc. he 

 obtains a small wound on the hand, and local gangrene and 

 necrosis set in, but death follows in the severer forms from a 



