WHAT'S HOT
Prev | Current Page 149 | Next

Various

"Scientific American Supplement, No. 441, June 14, 1884."

The fungus thus detected, was examined by Professor
Oudemans, who ascertained it to be a new species of Coryneum, and has
named it _Coryneum Beijerincki_. The inoculation experiments are best
made by means of incisions through the bark of young branches of
healthy peach trees or cherry trees, and by slightly raising the cut
edge of the bark and putting under it little bits of gum from a
diseased tree of the same kind. In nearly every instance these wounds
become the seats of acute gum disease, while similar wounds in the
same or other branches of the same tree, into which no gum is
inserted, remain healthy, unless, by chance, gum be washed into them
during rain. The inoculation fails only when the inserted pieces of
gum contain no Coryneum. By similar inoculations similar diseases can
be produced in plum, almond, and apricot trees, and with the gum of
any one of these trees any other can be infected; but of many other
substances which Beijerinck tried, not one produced any similar
disease. The inoculation with the gum is commonly followed by the
death of more or less of the adjacent structures; first of the bark,
then of the wood. Small branches or leaf stalks thus infected in
winter, or in many places at the same time, may be completely killed;
but, in the more instructive experiments the first symptom of the gum
disease is the appearance of a beautiful red color around the wound.


Pages:
137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161