224 MICRO-ORGANISMS AND DISEASE [chap. 



bacillus of human typhoid on gelatine, Agar, in milk and 

 potato, Loffler called it bacillus typhi murium. Successful 

 experiments with cultures were made in Thessaly to produce 

 wholesale infection and destruction of field mice then 

 infesting the agricultural districts of that country. 



Of the same nature appears to be the bacillus isolated by 

 H. Laser (Centralblatt f. Bakt. und Parasit., vol. xi., p. 184), 

 and which he found in a fatal epidemic amongst field mice 

 kept in the laboratory. The morphological and cultural 

 characters of the microbe, its virulence on mice, and the 

 post-mortem appearances in these animals coincide with / 

 Loffler's bacillus typhi murium. 



9. Bacillus of Oriental or bubonic plague. — This is at 

 present the only known species of this group which affects 

 the human subject. As shown by Kitasato and Yersin, the 

 bacillus of the inflamed lymph-glands (bubo) and also of the 

 blood, but principally the former, contain in pure culture an 

 abundance of short rod-like bacilli, which in shape and size, in 

 cultural characters, in plate and in streak on gelatine, and in 

 their effect on rodents belong clearly to the above group of 

 non-sporing, non-liquefying bacilli. The bacillus is non- 

 motile, and its effect on the rodent (guinea-pig) is to produce 

 acute heemorrhagic, septicsemic infection and death. 



Group B. — A second group comprises species which in 

 many points resemble the bacillus coh,i but differ from it in 

 this particular that they are capable of producing acute 

 infection and death of the animal body. Like bacillus coli, 

 the microbes of this group grow rapidly in gelatine plate 

 and gelatine streak and stab, and the appearances herein 



' It must be distinctly understood that I do not and cannot say 

 whether the various species I am about to describe are or are not 

 A-arieties of bacillus coli, for the characters by which this last is 

 identified are, after all, only comparatively few, besides being artificial; 

 it is more for convenience that we speak of " varieties " of b. coli. 



