MOLDS. 



single chain of conidia, in other species (called by some authorities 

 Sterigmatocystis) three or four secondary sterigmata which bear the 

 conidial chains. Part of the species produce also thin- walled perithecia 

 as yellow or brown spherical bodies upon the surface of the substrata. 

 These perithecia are filled with eight-spored asci (Fig. 5). A few species 

 produce sclerotia instead of asci, but many species are not known to 

 produce either perithecia or sclerotia. 



Important Species. Among the species constantly met with, Aspergillus 

 niger is recognizable by its black or very dark brown spores and in some 



FIG. 5. 



FIG. 5. Aspergillus glaucus. a, Con- 

 idiophore showing increased diameter over 

 the vegetative cells at its base (Xi28); 

 b, sterigmata (X45o); c, conidia, smooth 

 thick walled in this variety, other varieties 

 are spmy,(X45o); d, perithecium (Xi28); 

 , ascus containing ascospores (X45o). 

 (Original.) 



FIG. 6. 



FIG. 6. Aspergillus. (i) A. fumi- 

 gatus, Fres; (2) A. nidulans. i and 

 2 show the complete sterigmata of 

 A fumigatus and the secondary sterig- 

 mata of A. nidulans. The conidia of 

 these species do not remain attached in 

 ordinary fluid mounts. (Original.) 



strains by black sclerotia. Several black-scored forms are described, but 

 their separation is usually impossible from the data given. Aspergillus 

 niger ferments sugar solutions with the production of oxalic acid in con- 

 siderable quantity. 



Of green forms, Aspergillus glaucus, Link (Aspergillus herbariorum, 

 Wiggers), and Aspergillus repens, De Bary, both produce abundant 

 yellow perithecia. These abound upon herbarium specimens, hay, 

 grain, concentrated foods, such as jellies, preserves, and dried meats 

 upon which they produce green conidial areas which are later dotted with 

 bright yellow perithecia. 



Aspergillus fumigatus, Fresenius, is a green form characterized by 



