ASPERGILLUS NIGER. Van Tieghem. 



Origin. In putrid organic substances ; in lungs of 

 birds. 



Color. Black or dark brown. 



Mycelium. The arrangement is much the same as 

 in penicillium. 



Fruit-organs. The fruit hyphse are swollen or 

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

 covered willi radially arranged minute bottle-shaped 

 bodies the intermediate spore bearers or sterigmse from 

 which rows of spores extend. Sterigmee divided. 



Growth. Slow. 



Bread flasks Forms a slow growth which becomes very black. 



Temperature. Its optimum is about 35 C. 



Pathogenesis. Intravenous injection of spores in 

 rabbits is not followed by as malignant results as with the 

 next two forms. 



ASPERGILLUS FLAVESCENS. Wreden. 



Origin. White bread. 



Color. At first whitish, eventually pale yellow. 



Mycelium. The mycelial threads and spores are 

 smaller than those of A. niger. 



Fruit-organs. The club shaped ends of the fruit 

 hyphge are covered with sterigmae, from which extend 

 rows of spore?, as in A. niger. 



Growth. Rapid. 



Bread flasks. Grows best on bread. Forms a yellowish, low growth. 



Temperature. Optimum about 28 C. Grows well 

 in incubator. 



Pathogenesis. Is more pathogenic than A. niger, 

 and less than A. fumigatus. 



