194 A MANUAL OF THE ASPERGILLI 



individual pathogenic molds isolated by persons unfamiliar with the litera- 

 ture are rarely definite enough to separate nearly related forms. 



An occasional culture of A. versicolor is obtained from apparently patho- 

 genic sources. Thus far experimental work has not shown evidence of 

 actual lesions in human flesh. Little colonies bearing green heads and 

 conidia were drawn with a breast pump from an inflamed mammary gland 

 and kept in culture for many years but failed to grow in laboratory media at 

 blood heat, Aspergillus versicolor var. glauca Blochwitz was isolated from 

 human skin showing "ringworm" at the skin clinic in Kiel, but apparently 

 pathogenicity was not proved experimentally. Strains of A. versicolor are 

 frequently observed upon dried salted lean beef, thus showing its capacity 

 to grow in and upon meat products, but not giving direct evidence of par- 

 ticipation in any pathological process. 



Occurrence and Economic Importance 



Members of the Aspergillus versicolor group appear widely distributed in 

 soil, on spoiling and drying food stuffs, breads, cereals, old cheese, dried 

 meats, cured India rubber, musty vegetable products, and other substrata 

 characterized by a moderately low water content or containing factors toxic 

 to most organisns. They are reported as capable of decomposing certain 

 paraffins. The production of proteolytic enzymes by most strains is shown 

 by the digestion of milk and the liquefaction of gelatin. Aspergillus 

 sydowi, in particular, is a characteristic component of all soil examined. 



Fat production by .4. sydowi has been studied quite extensively by Pro- 

 fessor Peterson and associates at the University of Wisconsin. For reference 

 to this work see the various papers listed in the Topical Bibliography under 

 the heading "Chemistry of Mold Tissues." 



