IN SUSCEPTIBLE ANIMALS. 515 



Cornevin and Kitt have shown that the contents of the intestine 

 also contain the bacilli in large numbers, and the disease appears to 

 be propagated among swine principally by the contamination of their 

 food with the alvine discharges of diseased animals. 



Pigeons are very susceptible to the pathogenic action of this ba- 

 cillus, and usually die within three or four days after inoculation 

 with a pure culture. Rabbits are not so susceptible, although a 

 certain proportion die from general infection after being inoculated 

 in the ear. The first effect of such an inoculation is to produce an 

 erysipelatous inflammation. When the animal recovers it is subse- 

 quently immune. 



White mice and house mice are extremely susceptible, but field 

 mice are immune. This remarkable fact was first ascertained by 

 Koch by experiments with his bacillus of mouse septicaemia. House 

 mice which have been inoculated with a minute quantity of a pure 

 culture of the rothlauf , or mouse septicaemia, bacillus, die in from 

 forty to sixty hours. The animal is usually found dead in a sitting 

 position, with its back strongly curved, and for many hours before 

 death it remains quietly sitting in the same position ; the eyes are 

 glued together by a sticky secretion from the conjunctival mucous 

 membrane. At the autopsy the spleen is found to be very much en- 

 larged, and there may be a slight amount of oedema at the point of 

 inoculation. 



The bacilli are found in the blood vessels generally, and are very 

 numerous in the interior of the leucocytes, which are sometimes com- 

 pletely filled with them. 



BACILLUS COPROGENES PARVUS. 



Synonym. Mauseseptikamieahnlicher Bacillus (Eisenberg). 



Obtained by Bienstock from human faeces. 



Morphology. A. very minute bacillus, which is but little longer than it 

 is broad, and might easily be mistaken for a micrococcus. 



Biological Characters. Grows very slowly on nutrient gelatin, forming 

 a scarcely visible film along the line of inoculation, which at the end of 

 several weeks is scarcely one millimetre wide. Is not motile. 



Pathogenesis. In white mice an extensive oedema is developed at the 

 point of inoculation at the end of ten or twelve hours, and the animal dies 

 within thirty- six hours. The bacilli are found in great numbers in the 

 effused serum at the point of inoculation and in comparatively small num- 

 bers in the blood. A rabbit inoculated with a pure culture obtained from a 

 mouse died at the end of eight days. The inoculation, which was made in 

 the ear, gave rise to a local erysipelatous inflammation. 



