MOLDS 



55 



the production of oxalic acid in considerable quantity. Citric acid 

 fermentation with Aspergillus niger has been successfully developed 

 upon a factory basis by Currie in the United States. 



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, dried bread and 

 dried meats upon which they produce green conidial areas which are 

 later dotted with bright yellow perithecia. 



FIG. 35. FIG. 36. 



FIG. 35. Aspergillus glaucus. a, Conidiophore 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); d, peri thecium(X 128); 

 e, ascus containing ascospores (X45o). (Original.) 



FIG. 36. Aspergillus. (i) A. fumigatus, Fres; (2) A. nidulans. i and 2, Show 

 the simple sterigmata of A . fumigatus and the secondary sterigmata of A. nidulans. 

 The conidia of these species do not remain attached in ordinary fluid mounts. 

 (Original.) 



Aspergillus fumigatus, Fresenius, is a green form characterized by 

 short conidiophores enlarging gradually into heads and bearing a single 

 set of sterigmata on the very apex, with chains of thin-walled green 

 spores about 3^f m diameter. This sppcies produces a destructive 

 disease of birds known as aspergillosis. The same species is sometimes 

 reported as pathogenic to man. 



Aspergillus nidulans differs by having two sets of sterigmata but 

 otherwise frequently closely resembles Aspergillus fumigatus. It is 



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

 repens is the usual green form in this country. 



1"The unit of measurement is the micron GO or micro-millimeter (.001 mm. or J-Ssooo in.) 



