SCT. Le?- OR BU DS.
LU)
dexes of the numerous buds, as they pafs down to fhoot their radicles into the earth; and that the folid timber of a tree ceafes to be alive; and is then only of fervice to fupport the numerous family of buds in the air above the herbaceous vecetables in their vicinity.
A bud of a tree therefore, like a vegetable arifing from a feed, confifts of three parts; the plumula or leaf, the radicle or root-fibres, and the part which joins thefe two together; which 1s called the caudex by Linneus when applied to intire plants; and may, therefore, be termed caudex semmæ when applied to buds.
In herbaceous plants the caudex is generally a broad flat circular plate, from which the leaf-ftem afcends into the air, and the radicles or root-fibres defcend into the earth. Thus the caudex of a plant of wheat lies between the ftem and the radicles, at the bafs of the lowermoft leaf, and occafonally produces new flems and new radicles
from its fides. Thus the caudex of the tulip lies beneath the prin<:
cipal bulb, and generates new fmaller bulbs in the bofom of each bulb-leaf, befides one principal or central bulb; the caudex of orchis, and of fome ranunculufes, lies above their bulbous roots; whereas the caudexes of the buds of trees conftitute the longitudinal filaments of the bark, reaching from the plumula or apex of the bud on the branch to the bafe of it, or its root-fibres beneath the foil.
Noris this elongation of the caudexes of the buds of trees unana- logous to what bappens to fome herbaceous plants, as in wheat; when the grain is buried two or three inches beneath the foil, an elonga- tion of the caudex occurs almoft up to the furface, where another fet of fibrous roots are protruded, and the upright ftem commences. The fame happens to tulip-roots when planted too deep in the earth, as I have witnefled, and I fuppofe to thofe of many other vege- tables.|
This caudex of the buds of trees not only defcends as above de- fcribed, but alfo afcends from each bud to that above it; as on the
B 2 long