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der the question of Australian
unity, and on his return was appointed minister of defence in the first
government of the Australian Commonwealth. He did not long survive the
accomplishment of his political aims, dying at Sydney on the 10th of
January 1901, in the midst of the festivities attending the inauguration
of the new state.
DICOTYLEDONS, in botany, the larger of the two great classes of
angiosperms, embracing most of the common flower-bearing plants. The
name expresses the most universal character of the class, the importance
of which was first noticed by John Ray, namely, the presence of a pair
of seed-leaves or cotyledons, in the plantlet or embryo contained in the
seed. The embryo is generally surrounded by a larger or smaller amount
of foodstuff (endosperm) which serves to nourish it in its development
to form a seedling when the seed germinates; frequently, however, as in
pea or bean and their allies, the whole of the nourishment for future
use is stored up in the cotyledons themselves, which then become thick
and fleshy. In germination of the seed the root of the embryo (radicle)
grows out to get a holdfast for the plant; this is generally followed by
the growth of the short stem immediately above the root, the so-called
"hypocotyl," which carries up the cotyledons above the ground, where
they spread to the light and become the first green leaves of the plant.
Protected between the cotyledons and terminating the axis of the plant
is the first stem-bud (the plumule of the embryo), by the further growth
and development of which the aerial portion of the plant, consisting of
stem, leaves and branches, is formed, while the development of the
radicle forms the root-system. The size and manner of growth of the
adult plant show a great variety, from the small herb lasting for one
season only, to the forest tree living for centuries. The arrangement of
the conducting tissue in the stem is characteristic; a transverse
section of the very young stem shows a number of distinct conducting
strands--vascular bundles--arranged in a ring round the pith; these soon
become united to form a closed ring of bast and wood, separated by a
layer of formative tissue (cambium). In perennials the stem shows a
regular increase in thickness each year by the addition of a new ring of
wood outside the old one--for details of structure see PLANTS: Anatomy.
A similar growth occurs in the root. This increase in the diameter of
stem
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