es of the vegetable world, as well as those of the animal,
are excitable into a variety of motion by irritations of external objects.
This appears particularly in the mimosa or sensitive plant, whose leaves
contract on the slightest injury; the dionaea muscipula, which was lately
brought over from the marshes of America, presents us with another curious
instance of vegetable irritability; its leaves are 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. See Botanic Garden,
Part II. note on Silene.

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 nut-shell the sweet kernel 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 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 barks 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