52 
MILDEWS, RUSTS AND SMUTS 
Capnodium footii, Berk, and Desm. Forming rather 
small, circular, jet-black, more or less velvety patches on 
living leaves, mycelium consisting of interwoven monili- 
form hyphae ; perithecia ?, bristle-shaped, surrounded at 
the base by somewhat hyaline, moniliform threads ;• asci 
and spores unknown. 
Syn. Fujjiago fagi, Pers. 
Common on living leaves of the beech {Fagus sylvatica) 
and many evergreen trees, also on living leaves of Dogs’ 
mercury— {Mercurialis perennis ). 
A very unsatisfactory species. 
Europe generally. 
Capnodium elongatum, Berk, and Desm. Forming black, 
bristly or velvety patches on living leaves, mycelium inter¬ 
woven, moniliform ; perithecia elongated, mouth narrow 
and usually torn into shreds; asci ?; spores coloured, 2—3- 
septate, becoming muriform. 
On living lea^^es of species of Populus, Pynis, Tussilago 
farfar a. 
Europe generally. United States. 
UREDINACEAE 
The members of this family are all true parasites, and are 
popularly known as “ rusts ” and “ cluster-cups.” They 
are remarkable, even amongst the fungi, for the number and 
variety in form of spores or reproductive bodies possessed 
by many species, as also for the peculiar property, possessed 
by some, of passing one phase of their existence on a parti¬ 
cular host-plant, then migrating to another host-plant to 
complete the cycle of their development. All the species 
come under the category of “ microscopic fungi,” although 
the effects produced by some species on the host-plant 
render them sufficiently conspicuous. 
The destruction caused to cultivated crops by these 
parasites has been known from early times, in fact, long 
before it was knowm that they were fungi, and unfortunately, 
even at the present day, but few practical methods for 
preventing their ravages, have been discovered. A some¬ 
what detailed account of the various parts collectively 
constituting a member of this family, is necessary to form 
a clear conception of the mode of life followed. 
Vegetative portion. 
According to the popular idea, the visible portion of a 
fungus represents the entire plant ; this is a mistake. 
