SYSTEMATIC AND DESCRIPTIVE. 235 



mortem appearances, but the bacteria abound in the 

 blood. They were isolated from earth. 



Bacterium of septicaemia in rabbits (Bacillus 

 cuniculicida, Koch). Short rods, slightly pointed at 

 both ends ; in width '6 ju, 7 /*, in length i -4 ju,. They 

 stain deeply at the ends, leaving an uncoloured in- 

 terval in the middle (Fig. 81), an appearance which 

 must be distinguished from a diplococcus or figure 

 of eight. Two or more bacteria may be linked 

 together in a chain. They may be cultivated in 

 bouillon, blood serum, and nutrient gelatine. In 

 plate-cultivations of the latter, they produce dot- 



FIG. 81. BACTERIUM OF RABBIT SEPTICAEMIA; BLOOD OF SPARROW, 

 X 700 [after Koch]. 



like colonies, and in test-tubes little spherical 

 masses in the needle track, and a layer on the free 

 surface. The smallest quantity inoculated subcu- 

 taneously or in the cornea of a rabbit produces 

 a rise of temperature and laboured breathing after 

 10 12 hours, and death in 16 20 hours. The 

 spleen and lymphatic glands are found to be en- 

 larged, and the lungs congested, but no extravasa- 

 tions, and no peritonitis. In the blood the charac- 

 teristic rods abound, and in sections they are found 

 in the vessels and capillaries. Mice and birds are 

 very susceptible ; guinea-pigs and white rats have 



