120 



CLASSIFICATION OF THE MICRO-ORGANISMS. 



substratum the second period at once begins ; after 

 absorption of the store material the ascogonium enlarges 

 and sends out branches which finally develop into 

 asci containing spores. In the eurotium forms, on the 

 other hand, very delicate perithecia .form in the place 

 of the tough sclerotia, and present the appearance of 

 refracting clear yellow or sulphur yellow transparent 

 bodies of the size of a grain of sand with an enveloping 

 membrane which is very easily crushed. 



The sclerotia of the true aspergilli are found in old 



Fig. 9. Aspergillus glaucus. (After de Bary.) 



yJ, portion of a mycelium thread (m) with a conidia bearer (c) and a 



young Eujotium perithecium (F) X 190. 

 2?, ', conidia bearer with basidia and conidia. J5, some of the basidia 



more highly magnified. 



C, ascogon surrounded by the pollinodia. 



D, young perithecium cut longitudinally ; w, the future wall ; f, the 



store material X 250. 



E, an ascus with spores from a perithecium X 600 



cultivations (for example on brown bread) arranged in 

 nests in those places where there is incomplete access 

 of air, and where therefore conidia bearers do not grow ; 

 they form granules 0*5 1'5 mm. in diameter, and of 

 irregular form. Usually, however, only the conidial 



