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AGRICULTURAL AND INDUSTRIAL BACTERIOLOGY 



cover the entire end and frequently the entire swollen por- 

 tion of the conidiophore, giving it something of the appear- 

 ance of a war club covered with spikes. These sterigmata 

 in some species branch into groups of branches, and in other 

 species they give rise directly to the spores. The spores 

 are pinched off in chains from the tips of the primary or 

 secondary sterigmata. In some species the spores radiate 

 in all directions from the head, in others the chains cling 

 together giving rise to a long column of spores like a plume. 

 Many species of Aspergillus have been described. A few 

 of them are of considerable economic importance. The 



Fig. 41. — Species of Aspeegillus. a. View of conidiophore and 

 condia b. Longitudinal section through conidiophore to show 

 attachment and arrangement of sterigmata and conidia. c. 

 ■Conidia. 1. Aspergillus fumigatus. 2. A. niger. 3. A. glaucus, 

 (Adapted from Wehmer.) 



species known as Aspergillus fumigatus, for example, may 

 produce a type of pneumonia in birds when it is inhaled, 

 and it may also be pathogenic for other animals. Asper- 

 gillus niger has been much studied because of its ability to 

 produce a great variety of fermentative changes. The com- 

 monest is probably Aspergillus glaucus, a green species not 

 uncommon on canned fruits, jams, moldy grains, silage, 

 and in similar locations. It frequently produces abundant 

 yellow perithecia containing asci and ascospores. Asper- 

 gillus oryzae has been used in the manufacture of industrial 

 alcohol, for the conversion of starchy material into sugar 

 preliminary to the alcoholic fermentation. 



