APPENDIX. 229 



ASCOMYCETES. 



OidiumTuckeri. Fruit hyphse, bearing single ovoid 

 conidia. Observed in the form of brown patches, covered 

 with a white mildew- like layer on the leaves, branches, and 

 young fruit of the vine, producing a " grape-disease." 



Oidium lactis. Fruit hyphse, simple, erect, and 

 colourless, bearing at their ends a series or chain of 

 conidia (Plate XXIX., Fig. 5). In some cases the fruit 

 hypha branches beneath the chain of spores. Spores are 

 short cylinders, '0077 '0108 mm. long. The fungus 

 is sometimes found as a whitish mould on milk, bread, 

 paste, potato, and excrement, and is believed to be iden- 

 tical* with the fungus of certain human skin diseases, 

 Favus (Achorion ScJioenleinii}^ Herpes tonsurans (Tri- 

 cophyton tonsurans) and Pityriasis versicolor (Microsporon 

 furfur) (Plate XXIX., Fig. 6). Cultivated artificially in 

 nutrient gelatine, the conidia germinate into filaments of 

 varying length, which by subdivision form septate 

 mycelial hyphse ; these and their branches give rise in 

 turn to spores or conidia. The differences observed in 

 various diseases are attributed to differences in the nutrient 

 substratum. Othersf maintain that, in artificial cultiva- 

 tions of the spores of Tricophyton tonsurans^ the fructifica- 

 tion is identical with Penicillium. 



Oidium albicans. Vide Saccharomyces albicans. 



Aspergillus glaucus (Eurotium aspergillus glau- 

 cus). Mycelium, at first whitish, becoming grey-green 

 or yellow-green. Spores grey-green, thick-walled, '009 

 '015 mm. in diam. Sometimes found on various 

 substances, chiefly cooked fruit (Plate XXIX., Fig. 10). 



Aspergillus repens (Eurotium repens), De Bary. 

 Fruit heads fewer than in the above, which are at first 

 pale and then blue-green to dark-green in colour ; conidia 

 mostly oval, smooth, '005 *oo8 mm. long, colourless or 

 pale to grey-green. 



* Grawitz, Virchow' s A rchiv, vol. 70. 



t Morris and Henderson, Journ. Royal Microsc. Society. 1883. 



