810 BACILLI PATHOGENIC IN ANIMALS. 



Bacillus mimsepticus (Koch). 

 (Bacillus of Mouse Septicaemia.) 

 Bacillus of These organisms, first discovered hy Koch, and very 



mouse i i -IT iin 



septicaemia, closely resembling the bacilli of swine erysipelas, occur 

 not uncommonly in all sorts of mixtures of bacteria. 

 If small portions of putrefying fluids, which have been 

 exposed to the entrance of all kinds of bacteria, are 

 taken during the early stage of putrefaction and inocu- 

 lated subcutaneously into, say, twenty mice, one or other 

 of these animals generally dies of a septicaemia which is 

 caused by the bacilli of which we are speaking. 



The early symptoms of the disease are increased 

 secretion from the conjunctiva and adhesion of the eye- 

 lids, lassitude, &c. ; the animal sits quietly with the back 

 arched, and death occurs in this position 40 to 60 hours 

 after the inoculation, coming on almost imperceptibly 

 and without any convulsive movement. Even after 

 death the mouse generally remains in this position, 

 while the mouse which has died of anthrax, for example, 

 lies on its back or its side with its extremities stretched 

 out. On making a post-mortem examination slight 

 oedema is sometimes found at the seat of inoculation, 

 and there is also considerable swelling of the spleen, but 

 no further alterations. Delicate bacilli are present in 

 the neighbourhood of the seat of inoculation, in all the 

 blood vessels of the body, in the blood of the heart, and 

 more especially in the capillaries of the kidneys and 

 spleen. 



Morphological These bacilli are *8 to 1' p. in length, and about 

 characters. .% ^ t j n thickness. They often occur in pairs or in 

 fours, forming short threads ; they frequently form small 

 groups ; they have no spontaneous movement. They 

 can be rendered distinctly visible by treatment with the 

 aniline colours, which they readily take up ; cover-glass 

 preparations of blood are best stained in alkaline me thy - 

 lene blue, and then decolourised by momentary immer- 

 sion in very dilute acetic acid; Gram's method also 

 gives very distinct pictures. For sections the method 



