io62 FUNGI IMPERFECTI 



1896; Discomyces ntinutissimus P. Verdun, 1907; Microsporoides 

 ntinutissimus Neveu-Lemaire, 1906; Oospora minutissima Ridet, 

 1911. 



Mycelial threads extremely thin (o-6 /bc); seldom ramified. The 

 mycehal segments get easily dissociated, and have then the appear- 



FiG. 554. — Nocardia minutissima Fig. 555. — Cohnistreptohrix 



BuRCHARDT. tefiuis Castellani. 



Nocardia convoluta Chalmers and Christopherson, 1916. 



Nocardia. — -Gram-positive, but not acid-fast, without club 

 formations; found parasitic in man; easy of cultivation, growing 

 aerobically and anaerobically at 22° C. and 37° C, with a marked 

 preference for alkaline media, and with the production of good 

 but limited growths on the different agars, and the same at first on 

 blood serum and potato, on which, however, it becomes more pro- 

 fuse later. Not liquefying gelatine, but causing liquefaction of in- 

 spissated ox-blood serum, without diastatic action. Colonies usually 

 somewhat translucent when young, of a light to warm buff 

 colour (Ridgway's Plate XV., 17, 0-Y, f or d), and either con- 

 voluted or having the appearance of a jelly turned out of a mould, 

 later developing a whitish powdery efflorescence, without distinct 

 ociour, never pigmenting the medium on which it is grown; not 

 fermenting or peptonizing milk. Non-pathogenic for monkeys 

 and other laboratory animals. 



Remarks. — It is fairly frequently found in the actinomycotic type 

 of Madura foot in Khartoum, Anglo-Egyptian Sudan. 



Nocardia nigra Castellani, 19 13. 

 Nocardia, Gram-positive, some strains acid-fast, no definite club formations. 

 Grows aerobically and anaerobically at 22"* C. and 35° C. Colonies on maltose 

 agar and ordinary agar are black. Most strains liquefy gelatine. 



Nocardia lutea was found by Christopherson and Archibald in 1918 in the 

 lachrymal canal of a case in Khartoum. 



