MOLDS. 



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 perithecia, but many species are not known 

 to produce either perithecia or sclerotia. 



Important Species.- Among the species constantly met with, Aspergittus 

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



FIG. 5. 



FIG. 5. Aspergittus 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 spiny (X45o)i d, perithecium (XiaS); 

 e, ascus containing ascospores (X4So). 

 (Original.) 



FIG. 6. 



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

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

 2 show the simple sterigmata of A. fumi- 

 gatus and the secondary sterigmata of A . 

 nidulans. The conidia of these species 

 do not remain attached in ordinary fluid 

 mounts. (Original.) 



strains by black sclerotia. Several black-spored 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 fumi gatus, Fresenius, is a green form characterized by 



* Recent examination of a large number of American specimens shows that Aspergillus 

 repens is the usual green form in this country. 



