Plate VI 



A (upper left), Aspergillus Candidas Link, XRRL No. 308. B (upper right), Aspergillus niger group, strain 

 NRRL No. 67. C (center left), Tan-spored mutant of strain 67 produced bv ultraviolet radiation. D (center 

 " g D d' As P er illus arenaceous Smith, NRRL No. 517. E flower left ), Aspergillus alhaceus Thorn and Church. 

 XRRLN'o. 315. F (lower right), Aspergillus wentii Wehmer, NRRL No. 375. All cultures growing upon 

 Czapeks solution agar. (Color photographs by Haines, Northern Regional Research Laboratory. Repro- 

 duced through co-operation of Chas. Pfizer & Co., Inc.) 



