ERYSIPHE OlDIUiT. 131 



tivations, we see a maze of jointed threads which are 

 terminated by oval cells somewhat flask-shaped, or in 

 some cases more spherical. 



Special spore-bearing hyphae or distinct spore forma- 

 tion have not as jet been observed. Inoculation of mice 

 with small quantities of cultivations carried through a 

 considerable number of tubes gave rise in all cases to the 

 peculiar disease just described; inoculation of a cock 

 was tried without result. 



Cultivations made from human favus furnished 

 appearances on the whole microscopically and macro - 

 scopically similar, but not identical ; the investigations 

 on this point are not yet concluded. All these three 

 fungi probably belong to one species, and are in some 

 respects closely allied to the oidium fungi, but they 

 appear to differ among themselves as well as from the 

 Oidium lactis, as shown, for example, by the differences 

 in their temperature optima. 



The fungus of thrush was formerly described under the 

 name of Oidium albicaiis, and placed among these fungi. 

 Recent investigations render it, however, probable that the 

 thrush fungus belongs to the yeast fungi. 



2. Mucorineae (order : Zygomycetes). Very widely 

 distributed ; on putrefying substances they form white 

 or brown patches of mould, which consist of delicate 

 mycelium and fruit hyphae given off at right angles. 

 At the apex of the latter a globular sporangium is 

 formed, the protoplasm of which breaks up into a large 

 number of spores. The membrane of the sporangium is 

 at first colourless, but later it usually becomes blackish, 

 and when the sporangium is ripe it dissolves in water. 

 Many mucorineae form zygospores by the copulation of 

 two mycelium branches ; there is often also a formation 

 of gemmae. Among these we may mention: Mucor Saprophytic 

 mucedo. Fruit hyphae colourless, simple or branched, forms of 

 V 13 cm. long; sporangia yellowish- brown to black ; 



