750 



Blastomycosis 



by greatly diluting the culture material, so as to separate the 

 contained organisms widely. 



Many culture-media prove appropriate, glycerin agar-agar and 

 agar-agar containing i per cent, of dextrose being excellent. When 

 once isolated the organism is easily kept growing by transplanting 

 every month or two. 



The colonies appear in a few days as small round hemispheric dots 

 with numerous prickles about the surfaces. Later they have a 

 moldy appearance from the development of aerial hypha. They are 

 almost purely aerobic, those on the surface growing well, those 

 deeply seated in the medium scarcely at all. 



Agar-agar Slants. These at first show a creamy white layer that 

 becomes quite thick, and is moldy and fluffy on the surface. After 



Pt> 

 - 4^)\ Tfe# 



Mrilr i 



Fig. 313. Blastomyces dermatitidis. Budding forms and mycelial growths 

 from glucose agar (Irons and Graham, in "Journal of Infectious Diseases"). 



a few weeks the agar-agar begins to turn yellow and later may be- 

 come brown, though the growth itself remains white and unchanged. 

 The growth is firmly attached to the agar. When old, the growth 

 wrinkles. 



Bouillon. 'The growth is not luxuriant. The medium is not 

 clouded and contains fluffy flocculi of stringy viscid material. 

 Sugars added to the medium may be fermented. 



Gelatin. Growth takes place with aerial hypha. Liquefaction 

 does not occur or is very slow. 



Potato. Abundant growth with aerial hypha. 



Milk. Not coagulated, not acidified, slowly digested. 



There is some difficulty in describing the cultures, as different 

 authors describe them quite differently, evidently having different 

 organisms or different strains under observation. 



