Special M orphology and Classification. 275 
to the orifice of a stoma, and quickly multiplies there, form- 
- ing a white mould which is the cause of a great variety of 
unhealthy conditions. 
The disease caused by <Achorion Schenlemnt, called 
‘Favyus,’ usually attacks the part of the head of man which 
is covered with hair, and produces there the characteristic 
straw-coloured crab’s-eye-shaped incrustations ; and since its 
spores grow into the hair, this obstinate disease ends in 
complete and permanent loss of hair. ‘The phenomena are 
similar of Herpes tondens or tonsurans, which also attacks 
the hairy part of the head. The spores of Z7rzchophyton tonsu- 
vans penetrate in enormous numbers into the hairs, make 
them brittle, and cause them to break off at the skin. All 
these diseases, as well as others which might be added, are 
contagious. Of the Fungi which inhabit the bodies of 
living animals, and with the development of which par- 
ticular diseases and modes of death of animals are con- 
nected, a number of different forms and species are known. 
It will be sufficient to state that Alerpes tondens may be con- 
veyed from men to animals, and wie versa; and that 
another Fungus, Botrytis basstana, is the cause of the mus- 
cardine-disease which is so destructive to silkworms. The 
diseases of plants caused by Fungi have already been 
alluded to. . | 
Saprophytic Fungi allied to the Schizomycetes are the 
cause of the phenomena of fermentation, decay, and putre- 
faction. ‘These processes of decomposition vary according 
to the organism which occasions them, even in the same 
substratum, many and perhaps all species of Fungi giving 
rise to a special decomposition of their own. As little 
allusion as possible will here be made to the confusion 
and uncertainty recently imported into these practically 
important questions. Even the most easily decomposable 
organic substances, such as albumen, blood, and milk, only 
decompose very slowly when protected from the access of 
Tea | 
