e armed with spines on their upper edge, and are spread on the
ground around the stem; when an insect creeps on any of them in its
passage to the flower or seed, the leaf shuts up like a steel rat-trap,
and destroys its enemy.[163]

"The various secretions of vegetables as of odour, fruit, gum, resin,
wax, honey, seem brought about in the same manner as in the glands of
animals; the tasteless moisture of the earth is converted by the hop
plant into a bitter juice; as by the caterpillar in the nutshell, the
sweet powder is converted into a bitter powder. While the power of
absorption in the roots and barks of vegetables is excited into action
by the fluids applied to their mouths like the lacteals and lymphatics
of animals.

"2. The individuals of the vegetable world may be considered as inferior
or less perfect animals; a tree is a congeries of many living buds, and
in this respect resembles the branches of the coralline, which are a
congeries of a multitude of animals. Each of these buds of a tree has
its proper leaves or petals for lungs, produces its viviparous or its
oviparous offspring in buds or seeds; has its own roots, which,
extending down the stem of the tree, are interwoven with the roots of
the other buds, and form the bark, which is the only living part of the
stem, is annually renewed and is superinduced upon the former bark,
which then dies, and, with its stagnated juices gradually hardening into
wood, forms the concentric circles which we see in blocks of timber.

"The following circumstances evince the individuality of the buds of
trees. First, there are many trees whose whole internal wood is
perished, and yet the branches are vegete and healthy. Secondly, the
fibres of the bark of trees are chiefly longitudinal, resembling roots,
as is beautifully seen in those prepared barks that were lately brought
from Otaheita. Thirdly, in horizontal wounds of the bark of trees, the
fibres of the upper lip are always elongated downwards like roots, but
those of the lower lip do not approach to meet them. Fourthly, if you
wrap wet moss round any joint of a vine, or cover it with moist earth,
roots will shoot out from it. Fifthly, by the inoculation or engrafting
of trees many fruits are produced from one stem. Sixthly, a new tree is
produced from a branch plucked from an old one and set in the ground.
Whence it appears that the buds of deciduous trees are so many annual
plants, that the bark is a contexture of th