264 FUNGI. 
slices of potato tubers, ctc., have been employed. Fresh horse- 
dung, placed under a bell glass and kept in a humid atmosphere, 
will soon be covered with Mfwcor, and in like manner the growth 
of common moulds upon decayed fruit may be watched ; but this 
can hardly be termed cultivation unless the spores of some indi- 
vidual species are sown. Different solutions have been proposed 
for the growth of such conditions as the cells which induce fer- 
mentation, to which yeast plants belong. A fly attacked by 
Empusa musce, if immersed in water, will develop one of the 
Saprolegnia. 
The Uredines and other epiphyllous Contomycetes will readily 
germinate by placing the leaf which bears them on damp sand, 
or keeping them in a humid atmosphere. Messrs. Tulasne and 
De Bary have, in their numerous memoirs, detailed the methods 
adopted by them for different species, both for germination of 
the pscudospores and for impregnating healthy foster plants. 
The germination of the pseudospores of the species of Podi- 
soma may easily be induced, and secondary fruits obtained. The 
germination of the spores of Tulletia is more difficult to accom- 
plish, but this may be achieved. Mr. Berkeley found no difficulty, 
and had the stem impregnated as well as the germen. On the 
other hand, the pseudospores of Cystopus, when sown in water 
on a slip of glass, will soon produce the curious little zoospores 
in the manner already described. 
The sporidia of the Discomycetes, and some of the Spheriacei, 
germinate readily in a drop of water on a slip of glass, although 
not proceeding further than the protrusion of germ-tubes. A 
form of slide has been devised for growing purposes, in which 
the large covering glass is held in position, and one end of the 
slip being kept immersed in a vessel of water, capillary attrac- 
tion keeps up the supply for an indefinite period, so that there is 
no fear of a check from the evaporation of the fluid. Even when 
saccharine solutions are employed this method may be adopted. 
The special cultivation of the Peronosporet occupied the atten- 
tion of Professor De Bary for a long time, and his experienc ca 
are dctailed in his memoir on that group,* but which are too 
* De Bary, ‘Ann. des Sci. Nat.” 4th series, vol. xx. 
