PATHOGENIC YEASTS. 363 



The streptothrix farcinica (also designated " bacille du farcin 

 des boeufs Nocard") likewise gives rise to the formation of a 

 branched mycelium, with air-hyphae and spores. Growth takes 

 place between 30 C. (86 F.) and 40 C. (104 F.) in the 

 presence of air. The fungus can be stained by Gram's method. 

 Upon agar whitish, dry scales form that subsequently become 

 yellow and finally confluent. Bouillon is not rendered turbid, 

 but presents flocculi. A similar change takes place in milk, 

 which is not otherwise altered. The farcin des boeufs is a 

 pseudo-tuberculous affection of the skin and the internal viscera 

 in cattle. Experimentally the streptothrix farcinica induces 

 pseudo-tuberculosis in cows, sheep, and guinea-pigs. 



PATHOGENIC YEASTS. 



The recognition of the pathogenic yeasts has been made only 

 within recent years, and is due especially to the labors of Busse, 

 Sanfelice, Curtis, and Rabbinowitsch. 



The following varieties of pathogenic yeasts have been found 

 in human beings: 



The saccharomyces hominis has been observed in an infectious 

 disease that began with subperiosteal inflammation of the tibia, 

 and finally terminated in the clinical picture of pyemia. The 

 organism appears in the form of round or oval cells, with double 

 contour and a capsule. Upon gelatin -plates it forms round, 

 projecting colonies that do not cause liquefaction ; upon agar, 

 a whitish deposit ; upon potatoes, a grayish-brown deposit ; in 

 bouillon, marked turbidity, with the formation of a membrane; 

 and upon blood-serum, a dewdrop deposit. The saccharomyces 

 hominis possesses the property of inducing fermentation of grape- 

 sugar, with the generation of alcohol and carbon dioxid. It is 

 pathogenic for guinea-pigs, inducing local suppuration, and for 

 mice, which die exhibiting septic manifestations. 



The saccharomyces subcutaneus tumefaciens has been cultivated 

 from a myxomatous tumor of the thigh. It consists of oval 

 or round cells that frequently possess a large, transparent cap- 

 sule. In gelatin stab-cultures development takes place in the 

 form of small colonies ; the .culture-medium is not liquefied. 

 Upon agar a thick, creamy deposit forms, and upon potatoes a 

 whitish deposit, later becoming brown ; upon beerwort-agar a 

 brownish coating, and upon beerwort, a dense sediment without 

 development of membrane-formation. The fungus has slight fer- 

 mentative activity for saccharose, generating ethylic alcohol and 

 acetic acid. This yeast is pathogenic for white mice and rats, in 

 which extensive local vegetation occurs. Microscopically, the 

 tumor-like formations present no true structure, but are found 

 to consist of enormous parasitic infiltrations. 



