440 APPLIED BACTERIOLOGY 



such as size and shape of the rods, and flagella, two to 

 eight, and further, owing to their non-liquefaction of 

 gelatine and the power to grow well in phenolated gelatine 

 and broth, and to the practical identity of their appearance 

 and rapidity of growth in gelatine plates, and in gelatine 

 streak, potato, and broth cultures, must, for the present, 

 be considered as bacillus coli, though on account of their 

 differing from the typical bacillus coli, in respect either of 

 gas-production in gelatine shake culture, or of clotting of 

 milk, or of indol-reaction, they must be considered as 

 varieties of that microbe. 



Pathogenesis. — Comparatively small amounts of a pure 

 culture of the colon bacillus injected into the circulation of 

 a guinea-pig usually cause the death of the animal in from 

 one to three days, and the bacillus is found in considerable 

 numbers in the blood. But when injected subcutaneously 

 or into the peritoneal cavity of rabbits, a fatal termination 

 depends largely upon the quantity injected. Klein states 

 (Eeport of the Local Government Board, 1895-96) that it 

 forms toxic substances which, when injected into the 

 animal body in sufficient amount, cause intoxication. This 

 intoxication is known as sapraemia, and it is characterised 

 by fall of temperature, vomiting, purging, muscular twitch- 

 ings, collapse, and death — post mortem there is found 

 severe congestion of the intestine, with watery contents. 

 Thus, if a broth culture of B. coli, after incubation at 

 blood-heat for four or five days, be sterilised (so that the 

 enormous mass of the colon bacillus that have developed in 

 the medium are killed), and 2 to 3 c.c. of it be injected sub- 

 cutaneously into a guinea-pig of about 250 to 300 grams 

 weight, it will produce the above symptoms and cause the 

 death of the experimental animal. 



Bacillus Enteritidis (Gartner).— This organism was first 

 obtained by Gartner, in 1888, from the tissues of a cow 



