THE ASPERGILLUS TERREUS GROUP 



199 



to light pinkish-cinnamon. Microscopically, the conidial structures ap- 

 proximate those of the species itself. Separation as a new variety is based 

 primarily upon the characteristic coloration of the growing colony. 



Fig. 57. Conidial structures of members of the Aspergillus terreus group, X 840. 

 A, A. terreus, type strain NRRL No. 255 (Thorn No. 164). B, A. terreus var. aureus, 

 NRRL No. 1923. d, C 2 , and C 3 , A. carneus, NRRL No. 1928, conidial heads vary 

 greatly in size. D u D 2 , and D 3 , A. niveus, NRRL No. 515, conidial heads of varying 

 dimensions. 



Type strain NRRL No. 1923 (fig. 16 D) was isolated from Texas soil 

 contributed by Dr. F. E. Clark. Additional strains showing approximately 

 the same cultural and morphological characteristics have been isolated 

 from soils collected in Arkansas and Arizona. In A. terreus var. aureus the 

 yellow coloring matter is lodged in the vegetative mycelium, and there are 

 no suggestions of hulle cells; in A. carneus, however, approximately the same 



