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A MANUAL OF THE ASPERGILLI 



scribed— including the observations essential in a species characterization. 

 For convenience such data may be indicated vertically upon a descriptive 

 sheet which is elaborate enough to include observations that are regarded 

 as useful. Measurements should be presented as ranges encountered in 

 the examination of many units, not as exact and single measurements of 

 individual cells or structures. 



Primary sterigmata 



measurements 



arrangement 



color 

 Secondary sterigmata 



measurements 

 Conidia 



color 



measurements 



markings 

 Perithecia 



color 



size 



shape 

 Ascospore 



color 



size 



markings 

 Sclerotia 



color 



size 



Aspergillus — identifying number or marks. 

 Culture medium or natural substratum 

 Temperature of incubation 

 Colony characters 

 Rate of growth 

 Texture 

 Mycelium 



submerged 

 floccose 

 color: above 

 reverse 

 Heads 

 color 

 form 



measurements 

 Conidiophore 

 length 

 diameter 

 wall: thickness 

 markings 

 color 

 Vesicle 

 shape 

 size 

 color 



With such a descriptive sheet before him, the user of the manual finds 

 that the Aspergilli have been arranged into a series of natural groups (fig. 

 20), each containing one to several species aggregates. Each group in- 

 cludes species with varieties, and at times mutants, having a series of es- 

 sential characters in common. These groups have been arranged as nearly 

 as possible in natural order, based upon the presence or absence of certain 

 contrasting intergroup characters. 



These major separating characters are usually evident and positive. 

 Nevertheless, individual species are found in which certain of these charac- 

 ters are reduced to vestigial or apparently suppressed, yet which show so 

 many characters allying them with a particular group that such placement 

 is more logical than any other. Such species must sometimes be arbitrarily 

 placed, and their possible affiliation with other groups indicated both in the 

 discussion of the species and in the discussion of the related group. 



