YEASTS AND MOULDS. 147 



intravenous injection perish in twenty-four to forty-eight hours, 

 the viscera being filled with mycelia. 



True Moulds. Fliigge has made five distinct divisions of 

 moulds. It will, however, serve our purpose to classify those 

 to be described under three headings : Penicillium, Mucor, and 

 Aspergillus. 



Penicillium Glaucum. 



Origin. The most widely distributed of all moulds, found 

 wherever moulds can exist. 



Form. From the mycelium, hyphens spring which divide into 

 basidia (branches), from which tiny filaments arise (sterygmata), 

 arranged like a brush or tuft. On each sterygma a little bead 

 or conidium forms, which is the spore. In this particular fungus 

 the spores in mass appear green. 



Growth. It develops only at ordinary temperatures, forming 

 thick grayish-green moulds on bread-mash. At first these ap- 

 pear white, but as soon as the spores form, the green predomi- 

 nates. Gelatine is liquefied by it. 



Mucor Mucedo. Next to the penicilliumglaucum, this is the 

 most common mould. Found in horse dung, in nuts, and 

 apples, in bread and potatoes as a white mould. 



Form. The mycelium sends out several branches, on one of 

 which a pointed stem is formed which enlarges to form a globu- 

 lar head, a spore-bulb, or Sporangium. The spore-bulb is par- 

 titioned off into cells in which large oval spores lie. When the 

 spores are ripe a cap forms around the bulb, the walls break 

 down and the wind scatters the spores, leaving the cap or 

 u calumella" behind. 



Growth. Takes place at higher temperatures on acid media. 



It is not Pathogenic. 



Achorion Schonleinii. 



Tricophyton Tonsurans. 



Microsporon Furfur, 



These three forms are similar to each other in nearly every 

 particular and resemble in some respects the oidium lactis, in 

 other ways the mucors. The first one, Achorion Schonleinii^ was 

 discovered by Schonlein in 1839, in Favus, and is now known as 

 the direct cause of this skin disease.- 



