634 PATHOGENIC MICROORGANISMS 



have met with almost insurmountable obstacles. Some of the forms 

 described, like that of Busse, have fermented sugars and have not 

 formed mycelia, while organisms like that of Gilchrist did not cause 

 fermentation in carbohydrate media, but, by their formation of my- 

 celia under certain conditions, have indicated their close relationship 

 or possibly their identity with the oidia, transitional forms between 

 the yeasts and the hyphomycetes. It is thus, in the light of our pres- 

 ent knowledge of these microorganisms, quite impossible to establish 

 within this group a distinct classification that is at all reliable. 



In considering the possible origin of blastomycotic infection in 

 animals and man, it is, of course, important that we should have some 

 knowledge as to the pathogenic properties of the yeast met with and 

 handled in daily life. Rabinowitsch, 1 with this in view, has investigated 

 the pathogenic properties of fifty different species of yeasts obtained 

 from fruit, manure, dough, and other sources, and among them found 

 only seven varieties that had any pathogenicity for rabbits, mice, or 

 guinea-pigs. In most of her successful inoculations, however, the 

 disease produced in the animals had but very little resemblance to the 

 blastomycotic conditions observed in man. 



i Rabinowitsch, Zeit. f. Hyg., xxi, 1895. 



