224 A MANUAL OF THE ASPERGILLI 



colored in the same shade. Conidial heads not crowded, globose. Conidio- 

 phores smooth, thick-walled, with upper portion more or less brown, about 

 1.5 mm. in length by 12 to 20m in diameter. Vesicles up to 40 to 50 m in 

 diameter, crushing readily. Sterigmata in two series; primary about 

 15 to 20m by 3 to 5m, sometimes larger, secondary about 8 by 2 to 3/jl. 

 Conidia 3 to 4m, thin-walled, globose or subglobose, smooth or nearly so, 

 almost colorless when viewed singly, pale yellowish to cinnamon in mass. 

 Diagnosis based upon culture NRRL No. 348 (Thorn No. 3534b) re- 

 ceived from . Schiemann as a mutation induced by introducing potassium 

 bichromate into the culture medium. Approximately the same mutant 

 appeared in Steinberg and Thorn's series of induced mutations (1939, 1940). 

 Occasional cultures close to A. cinnamomeus have ben obtained from un- 

 known sources in nature. 



Aspergillus niger mut. Schiemanni (Schiemann) n. comb. 



Synonyms: A. Schiemanni (Schiemann) Thom, Jour. Agr. Res. 7: 13. 

 1916. 

 A. fuscus Schiemann, in Ztschr. Induktive Abstam, u. 

 Vererbungslehre, Bd. 8, Heft Y 2 , p. 1-35, 16 fig. 2 pi. 

 (1 col.) 1912. 

 Not A. fuscus Bonorden (Bot. Ztg. Jahr. 19: 202. 1861); 

 Not S. fusca Bainier (Bui. Soc. Bot. France 27: 29, PI. 1, fig. 5. 

 1880) 



Colonies upon Czapek's solution agar at room temperature, rapidly 

 growing and spreading, developing a surface growth of conidiophores and 

 heads forming a crowded fruiting area 2 to 3 mm. deep in slanted tubes, 

 becoming a shade of brown near fawn color (Ridgway, PI. XL); reverse 

 yellowish (fig. 61 D). Conidial heads large, fairly crowded. Conidiophores 

 coarse, 2.5 mm. or more long by 15 to 25m wide. Vesicles up to 50 to 60m 

 in diameter. Sterigmata in two series; primary, 15 to 40m by 4 to 6m, 

 sometimes larger, secondary 7 to 8m by 2 to 3m- Conidia thin-walled, smooth 

 except sometimes a trace of markings, 3.5 to 4.5 or 5m in diameter. 



Culture NRRL No. 361 (Thom No. 3534C) was received from Schiemann. 

 Culture NRRL No. 362 was received from Biourge under the same name but 

 shows a much deeper brown color (near Natal brown, Ridgway, PI. XL). 



The mutant, A. niger mut. Schiemanni, is distinguished from the parent 

 type of A. niger by the color and smoothness of its spores. The name, 

 A . fuscus Schiemann, is invalidated by the prior usage of the names A . fuscus 

 by Bonorden and S. fusca by Bainier. 



Mutations of approximately this same type have been secured from 

 cultures of strain NRRL No. 67 (PL VI C) by ultra-violet irradiation 



