Bacillus. 



31 



Fig. 24. — a. Bacillus anthracts, from the blood of a 

 cow that had died of splenic fever, examined after 

 death ; b, B. ruber, X 600 (after Cohn). 



flagella ; cells 4 /a or more long, very slender, for the most 



part united into 



long, often bent, 



threads. Spores not 



at all or little thicker 



than the threads, 



I -5-2 -2 /A long. (Figs. 



20c, 23, 243.) 



In the blood of 

 animals which have 

 died of splenic fever ; 

 the cause of splenic fever in cattle, sheep, etc., and of 

 " pustula maligna," woolsorters' disease, in man. 



B. anthracis and the pathological phenomena engendered thereby 

 are the most accurately known of all the diseases induced by Schizo- 

 mycetes. The Bacilli are found without exception in the blood of 

 animals which have died of splenic fever, and it is sought to infer that 

 they are the cause of the disease. So long as only the vegetative 

 threads were known, it was difficult to prove this ; for these are capable 

 of living only a relatively short time, and blood which contains them 

 alone soon loses its power of infection. The remarkable thing about . 

 splenic fever, however, is that it often breaks out in a neighbourhood 

 quite suddenly, then disappears for a long time, to appear again just 

 as unexpectedly without any transference from without having taken 

 place. From these facts it must be concluded that the contagium can 

 preserve its infectiveness for a considerable time. The discovery of the 

 spores of B. anthracis, which nevertheless are formed only in the blood 

 of dead animals, or when the blood of animals affected with splenic 

 fever is slowly dried, explains this long-lasting power. For, moreover, 

 the spores of B. anthracis possess great capabilities of resistance to 

 external influences, especially to dryness, so that they are capable of 

 further development even after years. These spores are buried in the 

 ground with the bodies of diseased animals which have died, and when 

 there means of dispersion are open to them. If then they get in any 

 w4y into the bodies or the blood of cattle, etc., they germinate, the 

 rods which proceed from them multiply in abundance and soon com- 

 mence their destructive work. 



[This species is now known to move at one stage of its existence. 



