IDENTITY OF AMERICAN AND FRENCH SPOROTRICHOSIS 119 



have for some time made a study of ehromogensis 23 in these 

 cultures and have now some pure white strains which sprang 

 from deeply pigmented cultures. Indeed, from the culture 

 I received from Gougerot of Paris, a white colony appeared 

 which has remained pure white and smooth, and though tested 

 on numerous media of the most favorable sort (carrot, potato, 

 Sabouraud medium), remains pure white. Passage through 

 a rat for six weeks did not alter it. It has now passed through 

 twenty-four generations without change. The black colonies 

 continue to produce pigment as usual. Similar alterations 

 have been observed in other strains. Distinct and similar 

 changes have been noted in the Schenck-Hektoen strain but 

 they are less marked. It is interesting to note Gougerot 's 

 statement 23 in this connection: "Par exception nous avons 

 en des pleomorphismes blancs qui sont trestis irreductibles ; 

 ils etaient associes a des pleomorphismes de surface et ces 

 pleomorphismes complexes donnaient un Sporotrichum Beur- 

 manni, identique d 'aspect au Sporotrichum Schenckii. " 



A second pleomorphism relates to form of growth, smooth- 

 ness, wrinkling, etc. Colonies tend to lose their irregular 

 and corrugated surface and become smooth and leathery in 

 appearance. This is a common change in strains of sporo- 

 tricha. which can be brought about, at least to some extent, in 

 all strains by suitable culture, especially on ill adapted media. 



A third is the tendency to form on the surface growth hair- 

 like processes or finely pointed spines. This is seen quite 

 commonly and is a striking feature of many cultures of the 

 original Schenck-Hektoen strain. 



A fourth pleomorphic change is the appearance of a 

 powdery growth covering part or all of the media. The color 

 is variable and may range from black through brown to pure 

 white. This alteration is largely dependent on surface de- 

 posits of spores. 



It is to be emphasized that these pleomorphic changes above 

 noted are common. In some strains they are far more fre- 

 quent than in others, but probably occur in all strains at 



Davis, ./. inf. Dis., 17, p. 174, 1915. 

 23 Les Sporotrichoses, Paris, p. 91, 1912. 



