346 A MANUAL OF BACTERIOLOGY 



Cobbett, Petrie, 1 Williams, and Clark 2 have, however, 

 quite failed to confirm Salter's results. Thiele and 

 Embleton also claim to have effected the transformation of 

 a typical Hofmann bacillus into a virulent Klebs-Loffler 

 bacillus by massive intra-peritoneal inoculation of guinea- 

 pigs with Hofmann culture suspended in 30 per cent, 

 gelatin and after death of the guinea-pig, injection of the 

 peritoneal exudate with a smaller amount of living bacilli 

 into a second guinea-pig, and repeating this method of 

 inoculation. Finally the bacillus became Klebs-Loffler 

 in morphology and 1 c.c. of its toxin killed a guinea-pig 

 in forty-eight hours, and this toxin was neutralised by 

 diphtheria antitoxin. 



Others have been unable to convert the pseudo-bacillus 

 into a virulent Klebs-Loffler bacillus, or vice versa, and 

 many are of opinion that it has probably nothing to 

 do with diphtheria (Park and Beebe, Peters, Washbourne, 

 Cobbett, Clark). A few fatal cases have been recorded 

 (e.g. by Stanley Kent) in which a careful search has failed 

 to reveal any but Hofmann bacilli. Boycott 3 found that 

 the seasonal prevalence of the Klebs-Loffler and Hofmann 

 bacilli does not correspond, the former prevailing during 

 September, October, and November ; the latter is more 

 frequent from May to August. 



To sum up : the Klebs-Loffler-like avirulent bacilli met 

 with in the throat, the pseudo-diphtheria bacilli of Roux 

 and Yersin, are probably modified and avirulent diph- 

 theria bacilli. As regards the Hofmann bacillus, the 

 general trend of opinion at present is to consider it as 

 quite distinct from the Klebs-Loffler bacillus. Another 

 view is to regard it as in reality including several species, 

 of which one may be a modified Klebs-Loffler bacillus, 



1 Journ. of Hygiene, vol. v, p. 134. 



* Journ. Infect. Diseases, vol. vii, 1910, p. 335. 



3 Journ. of Hygiene, 1905, vol. v, p. 223. 



