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We know that all tendrils are either transformed
leaves, as in the case of the pea vine, where each branch of its
tendril represents a modified leaflet; or they are transformed
flower stalks or other organs. Occasionally the tendril of a
grapevine reveals its ancestry by bearing a blossom or a cluster
of flowers, and sometimes even fruit, about midway on the coil,
which attempts to fill all offices at once like Pooh Bah.
The phylloxera having destroyed many of the finest vineyards in
Europe, it would seem that Americans have the best of chances to
supply the world with high-class wines, for there is not a State
in the Union where the vine will not flourish. Here its worst
enemy is mildew, a parasitical fungus which attacks the leaves,
revealing itself in yellowish-brown patches on the upper side,
and thin, frosty patches underneath. Soon the leaves become sere,
and then they fall. The microscope reveals a miniature forest of
growth in each leaf, with the threadlike roots of the fungi
searching about the leaf cells for food.


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