ASPERGILLUS 



101 



were made. Identification of a species group only is, for most pur- 

 poses, in effect no identification at all; but it may satisfy the worker, 

 which was often unfortunately, and to Henrici's misgiving, the effect 



Fig. 49. Aspergillus fimiigaius (Xl^OO) : conidial head. Photograph by Dr. 



Kenneth R. Raper. 



of the key to species groups published in the first edition of this 

 book. Hence no key is given here. 



Aspergillus species are found on a wide variety of substrates. 

 They are numerous in soil and particularly so on dried vegetable 

 matter, as hay and grains. They can apparently tolerate very high 

 osmotic concentrations and extract their necessary water from rela- 

 tively dry substrates. In contrast to Penicillium they can, as a 



