CH. VIII] TRANSMUTATION IN THE LIVING BODY 109 



vestigators claim to have converted the Klebs-Loeffler type 

 of organism into the Hofmann type — by prolonged cultivation 

 (Lesieur, 1901), by growth at a high temperature (Hewlett and 

 Knight, 1897), by growth in the subcutaneous tissues of an 

 immune rat (Ohlmacher, 1902) and other methods — and main- 

 tain that the reverse change can be brought about by "passage" 

 (Lesieur, 1901, Hewlett and Knight, 1897, Ohlmacher, 1902, 

 etc.). Salter (1899) has stated that, by five successive passages 

 through goldfinches, he was able to convert four strains of 

 typical Hofinann's bacilli into no less typical Klebs-Loefiier 

 bacilli, the transformation being complete as regards virulence, 

 morphology and acid production, and in the power to form 

 a toxin neutralised by diphtheria antitoxin. 



Thiele and Embleton claim to have converted Hofmann's 

 bacillus into a bacillus morphologically indistinguishable from 

 the diphtheria bacillus and capable of secreting an exotoxin 

 which can be neutralised by diphtheria antitoxin. This was 

 accomplished by inoculating a succession of guineapigs with 

 an emulsion of Hofinann's bacillus containing a certain pro- 

 portion of gelatin, the organism being recovered from the 

 peritoneal cavity after each passage. 



As regards the fermenting properties of the two organisms, 

 Clark (1910) has shown that Hofinann's bacillus does produce 

 slight acidity in dextrose broth ; while Goodman (1908), by a 

 process of selection, obtained strains of the true diphtheria 

 bacillus which exhibited differences in fermenting power as 

 wide as those naturally existing between this organism and 

 Hofinann's ; and he concluded that the fermenting power was 

 a poor guide in determining whether an organism was a 

 pathogenic one or a harmless saprophyte. 



Finally, Boycott's statistics demonstrate (Muir and Ritchie) 

 that the period of maximal seasonal prevalence of Hofinann's 

 bacillus immediately precedes that of true diphtheria, and 

 Hewlett and Knight (1897) have offered evidence in support 

 of the opinion that Hofinann's bacillus is present in increasing 

 numbers in the throats of diphtheria patients during recovery 

 from the disease. 



Recent work by Graham Smith and others, and the inability 



