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 and fall of both 1871 and 1872, on the 
vines in the foreign Department grapery, the true fruit or peri- 
tbecia of Erysiphe Tuckeri. The Rev. 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 Tuckeri , and the name of Oidium 
Tuckeri should be rejected.” 
When Professor Plancbon visited this Department last year, I 
prepared for him a microscopic slide containing specimens of the 
perithecia of Erysiphe Tuckeri, 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 Tuckeri, on 
a knowledge of which depends the proper remedy to be applied 
for its destruction and the consequent protection of the vine. 
