M OF BUDS. 
the oi^'f^i't* being in the centre of the trunk, and the newest forming 
tlie outv*f layer. This kind of stem may be seen in the oak and other 
f(>renil tiees in our climate, and also in most of our common herba- 
ceoQA plants ; these spring from seeds with two cotyledons, and are 
called dicotyledonous, 
2d. Stems which grow internally, as palms and grasses: here the 
wood, instead of circhng around the first formed substance, is pushed 
outwards by the development of new fibres in the centre ; this kind 
of stem belongs to plants whose seeds have but one cotyledon, and 
are therefore called monocotyledonous.* 
LECTURE VIII. 
OF BUDS. 
Most leaves and flowers proceed from scaly coverings called buds 
The scales envelop each other closely ; the exterior ones being dry 
and hard, the interior moist, and covered with down ; they are also 
furnished with a kind of resin or balsam, which prevents the embryo 
from being injured by too much moisture. Buds have been known 
to lie for years in water ^ without injury to the germ within. 
The sap is the great fountain of vegetable life ; by its agency new 
buds are yearly formed to replace the leaves and flowers destroyed 
by the severity of winter. Branches also originate from buds. Lin- 
nseus supposed that buds spring from the pith, this being found ne- 
cessary to their formation and growth. The bud is a protuberance 
formed by the swelling of the germ ; and as, for this purpose, the 
agency of an additional quantity of sap is needed, we see the bud 
appearing at the axils of leaves, or the extremities of branches and 
stems, where there is an accumulation of this fluid. If you plant a 
slip of Geranium, you will observe that it either sprouts from the axil 
of a leaf, or from knots in the stem, which answer the same purpose 
as the leaf, by slightly interrupting the circulation of the juices, and 
thus aflbrding an accumulation of sap necessary for the production 
of a new shoot. 
Some botanists distinguish the diflTerent periods of the bud as fol- 
lows : first, the point in the plant which gives rise to the bud, is called 
the eye^ when this begins to swell and become apparent, it is termed 
the biition; and when it begins to unfold, the 6wd.t 
Herbs and shrubs have buds, but these usually grow and unfold 
themselves in the same season, anc are destitute of scales ; while the 
buds of trees are not perfected in less than two seasons, and, in some 
cases, they require years for their full development. Ifou have, no 
doubt, observed in the spring, the rapid growth of the leaves and 
branches of trees ; and perhaps, have also noticed, that as summer 
advances, the progress of vegetation seems almost suspended. But 
nature, instead of resting in her operations, is now busy in providing 
for the next year ; she is turning the vital energies of tr^e plants to 
* These two kinds of stem have by some French botanists been caWed exogenous 
and endogenous : these words are derived from the Greek ; the first signifying to grou 
exiernnlly, the second, to grow inlernally. 
f These terms in French, are Z'a?i/, the eye, bouton, the button, and bourgeons^ the 
bud. 
Dicotyledonous stems—Monocotyledonous stems— Desciiption of buds— Agency oi 
eap — The eye, button, and bud— Herbs and shrubs destitutt of scaly buds. 
