As chlorophyll, or
leaf-green, acts only under the influence of light and air, most
plants expose all the leaf surface possible; but a parasite,
which absorbs from others juices already assimilated, certainly
has no use for chlorophyll, nor for leaves either; and in the
broom-rape, beech-drops, and Indian pipe, among other thieves, we
see leaves degenerated into bracts more or less without color,
according to the extent of their crime. Now they cannot
manufacture carbohydrates, even if they would, any more than
fungi can.
On the beech-drop's slender branches two kinds of flowers are
seated: below are the minute fertile ones, which never open, but,
without imported pollen, ripen an abundance of seed with
literally the closest economy. Nevertheless, to save the species
from still deeper degeneracy through perpetual
self-fertilization, small purplish-striped flowers above them
mature stigmas and anthers on different days, and invite insect
visits to help them produce a few cross-fertilized seeds.
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