550 MEDICAL MYCOLOGY 



the Ehine valley; since the World War endemic also in Germany, Austria, 

 Hungary, and epidemic in Roumania. Occasional in Boston, Chicago, and 

 Australia ; rare in Sao Paulo, Brazil. 



Hyphae either straight or curved with clavate tips ; chlamydospores ter- 

 minal or intercalary, 5-7/a ; aleurospores 2-4/a ; closterospores rare, usually only 

 1-2-celled, very rarely up to 10-celled, 40-70 x 15-25ju,; rarely short spirals on 

 dextrin + peptone and on wheat flour. 



Colony a small velvety disc with a very small point in the center, reach- 

 ing 5 cm. in a month, white or light grayish (brown at 37° C.) ; with 3-4 radial 

 furrows, developing up to 10 intercalary radial furrows. After the colony 

 reaches about 8 cm. in diameter, the furrows disappear, and concentric circles 

 of long and short velvet form ; practically no pleomorphism present. On po- 

 tato, gray then reddish brown, smooth, moist, forming a velvet in about 10 days. 



Var. velveticmn (Sabouraud) Dodge, n. comb. 



Microsporum velveticum Sabouraud, Ann. Derm. Syphiligr. IV, 8: 178, 

 1907; Maladies du cuir chevelu 3: 170, 171, 1910. 



Aleurosporia velvetica Grigorakis, Ann. Sci. Nat. Bot. X, 7: 413, 1925. 



Producing tinea tonsurans microsporica ; not inoculable to guinea pigs, 

 rare in Paris where first described ; reported common in Louisiana by Cas- 

 tellani. 



Only aleurospores in compound thyrses observed. 



Colony whiter, drier, and thicker than in the species ; in age dividing into 

 5-6 sectors, remaining cottony but becoming slightly brownish. The older 

 colonies look much less like the species than the younger and maintain this 

 difference for 2 years. On potato, crowded velvety tufts, colony drier and 

 thicker than in M. Audouini. 



Sabouraud (1910) suggests that this variety may be only a pleomorphic 

 strain of M. Audouini. 



Var. tardum (Sabouraud) Dodge, n. comb. 



Microsporum tardum Sabouraud, Maladies du cuir chevlu 3: 172, 1910. 



Sdbouraudites tardus Ota & Langeron, Ann. Parasitol. Hum. Comp. 1: 

 328, 1923. 



Closteroaleurosporia tarda Grigorakis, Ann. Sci. Nat. Bot. X, 7: 415, 1925. 



Microsporum (Closteroaleurosporia) tardum Guiart & Grigorakis, Lyon 

 Med. 141 : 377, 1928. 



Producing tinea tonsurans microsporica; not inoculable into guinea pig; 

 known only from France and Montreal. 



Closterospores degenerate; aleurospores 2-3 times as long as they are 

 broad, arthrospores present; degenerate spirals and denticulate and pectinate 

 hyphae present. 



Colony appears as a dwarf M. Audouini, having half its dimensions, the 

 velvet shorter, drier, and thicker, suggesting a colony on unsuitable medium, 

 but these cultural characters seem constant. 



