MOULDS 231 



crete mammillated fluffy colonies. They consist under the micro- 

 scope of slender septate hyphae. 



Favus is due to the mould Achorion Schoenleinii. This fungus 

 gives off hyphae with knob-like reproductive organs. Spores are 

 oval 3~8/x X 3~4ju. This fungus grows as a "scutulum" on the 

 skin eruption. It can be cultivated on sugar agar, as a waxy, or 

 downy yellow or white round plate with a central mammillation. 



Pityriasis versicolor is due to the mould Microsporon furfur. 

 It is similar to the Trichophyta, but invades only the superficial 

 layers of the skin. 



Aspergillus Niger, A.Fumigatus, and A.Flavus. A polycellular 

 mycelial organism which produces spores and branched threads, 

 that are variously named from the macroscopic appearances of 

 the growth. All thrive well as 37C. and may be cultivated on 

 the usual culture media. In man, the external auditory meatus 

 is often infected with these organisms, causing a troublesome dis- 

 ease. They may infect the lungs of weak anaemic subjects with 

 wasting diseases, and may be pathogenic for cattle, horses, and 

 birds. 



The author has found that the young hyphae, the sporangiar 

 and spores of some of these hyphomycetes (moulds) if treated with 

 hot or boiling alkaline solution of copper sulphate are stained be 

 the copper, which has an affinity for them, and appear a light lilac- 

 blue under the microscope. If treated with a solution of ferric 

 cyanide of potash and acetic acid, these stained parts turn a 

 dark brown, showing that there is an actual absorption or per- 

 haps chemical union of the protoplasm of the mould with the 

 copper. Some moulds are stained a deep blue, and are visible 

 to the naked eye in test-tubes, after treatment with the boiling 

 alkaline copper others are colored a bright yellow. Some moulds 

 and bacteria have the power of reducing copper in Fehling's 

 "solution. 



