Certain Fungi Parasitic on Plants. 
125 
have I seen connected with them pycnidia, forms of a cell described 
and illustrated by Professor Amice and Doctor Plomley, of Europe, 
and represented by them as connected in some way with the 
Oidium. I am certain, however, that I have found in great pro- 
fusion, during the summer ana fall of both 1871 and 1872, on the 
vines in the foreign Department grapery, the true fruit or peri- 
thecia of Erysiphe Tucheri. The Eev. M. J. Berkley says : 
" It is true that the real sporangia of the vine mildew have not 
yet been observed We do not doubt, therefore, that at some 
future period the true sporangia may be found ; and we trust that the 
little parasite which has been of such unlooked-for importance may 
still preserve the specific name originally assigned to it, in honour 
of the meritorious cultivator who first observed it It may, 
therefore, be named Erysiphe Tucheri, and the name of Oidium 
Tuj'keri should be rejected." 
When Professor Planchon visited this Department last year, I 
prepared for him a microscopic slide containing specimens of the 
perithecia of Erysiphe Tucheri^ taken from a foreign vine of the 
Department grapery. 
Should the climatic condition of the summer and fall of 1875 
prove favourable for further investigation in this direction, I may be 
enabled to define more clearly the habits of Erysiphe Tucheri^ on 
a knowledge of which depends the proper remedy to be applied 
for its destruction and the consequent protection of the vine. 
