188 



INFECTIONS CAUSED BY MOLDS 



dermatitidis except that they are less uniform in size and shape and 

 are not so well differentiated from the ehlamydospores which are 

 also present. Strains vary, some producing a glabrous, wrinkled, or 

 vermiculate colony, others extending more widely over the agar sur- 

 face and being covered with short white aerial hyphae. 



Fig. 94. Blastomyces brasiliensis in 

 liver tissue (XHOO), showing periph- 

 eral small buds from parent cell. 

 Occasionally larger buds are formed. 

 Photomicrograph by Dr. N. F. 

 Conant. 



Fig. 95. Blastomyces brasiliensis from 

 beef infusion agar, 37°, X^OO. Some- 

 times multiple budding with large 

 peripheral cells is seen, like that 

 sometimes found in tissues. On 

 Sabouraud agar at room tempera- 

 ture, morphology is mycelial, very 

 like that of B. dermatiditis. Photo- 

 micrograph by Dr. N. F. Conant. 



Taxonomy. Since Splendore named the fungus Zymonema bra- 

 siliense it has been known under a variety of names, most familiar of 

 which is Paracoccidioides brasiliensis Almeida. Conant and Howell - 

 have called attention to the similarities between this fungus and 

 Blastomyces dermatitidis and have transferred it to the genus Blasto- 

 myces. Moore ^ described two additional species, but there is some 

 doubt whether these are more than minor and unstable variations of 

 B. brasiliensis. 



Geographical Distribution. The mycosis appears to be most com- 

 mon in Brazil and particularly in the state of Sao Paulo, but it is 

 known also in Argentina and other South American countries. 



Habitat. The habitat in nature of Blastomyces brasiliensis is un- 

 known. There is some evidence of direct transmission of the fungus 

 from man to man. 



