Aspergillus Niger, Van Tieghem. 



ORIGIN. In putrid substances; in the lungs of birds. 



COLOR. Black or dark brown. 



MYCELIUM. This is low and at first white, then brown- 

 ish or black. 



FRUIT-ORGANS. The fruit hyphse are spherical, or flask-, 

 or club-shaped at the end, and this enlargement is covered 

 with radially arranged, minute bottle-shaped bodies the 

 intermediate spore bearers or sterigmce from which rows of 

 spores extend. The sterigmae are divided. The spores 

 are black or brownish and spherical, and are 3-5 ft in 

 diameter. 



GROWTH. Slow. 



Bread flasks. It forms a low growth which becomes very black. 



TEMPERATURE. The optimum is about 35. 



PATHOGENESIS. Intravenous injection of spores in rab- 

 bits is not followed by as malignant results as with the 

 next two forms. It gives rise to diastatic, inverting and 

 other ferments. 



Aspergillus Flavescens, Wreden. 



ORIGIN. White bread. 



COLOR. At first whitish, eventually pale yellow or yel- 

 lowish green. 



MYCELIUM. The mycelial threads and spores are 

 smaller than those of A. niger. 



FRUIT-ORGANS. The club-shaped ends of the fruit 

 hyphae are covered with sterigmae, from which extend 

 rows of spores, as in A. niger. The spores are yellowish 

 or brownish in color and are 5-7 ft in diameter. 



GROWTH. Rapid. 



Bread flasks. Grows best on bread where it forms a yellowish, 

 low growth. 



TEMPERATURE. The optimum is about 28, but it grows 

 well in the incubator. 



PATHOGENESIS. It is more pathogenic than A. niger, 

 and less than A. fumigatus. 



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