aENERAL FACTS RELATING TO VEGETABLES. 
to form a genus, and genera together to form an order, and orders together to fcr\t 
a class, we then proceed by synthesis, which means putting together. 
23. General Facts relating to Vegetables. — ^The sol'-d part o\ 
plants, or tissue^ is composed chiefly of fibers and meiniyranes^ 
which form tubes and cells for conveying and containing fluids. 
When the fibrous portion predominates, the plant becomes 
'ongh and woody ; and when the cellular structure prevails, the 
product is tender and succulent. The various vegetable tissues 
will be considered more fully hereafter. Plants are furnished 
with pores {stomatd)^ by which they imbibe nourishment from 
surrounding bodies. The part which fixes the plant in the 
earth and absorbs from it the juices necessary to vegetation, is 
the root ; this organ is never wholly wanting. The stem^ or 
ascending axis, does not always rise ; it sometimes creeps upon 
the earth, or remains concealed in its bosom; but, generally, 
the stem ascends either by its own strength, or, as in the case 
of vines, by supporting itself upon some other body. The 
divisions of the stem are its branches / the divisions of 
the branches are bra/nclilets., or boughs. When the vegetable 
has no stem, the leaves, flower, and fruit grow from the tops 
of the root ; but when the stem exists, that, or its branches, 
bear them. Herbs in which cellula/r tissue abounds, have soft, 
watery stems, of short duration, which bear flowers once, and 
then die. Trees and shrubs^ being mostly formed of fibrous 
tissue^ have solid and woody stems ; they live and bear flowers 
rnany years. Small bodies of a round or conical form, consist- 
ing of thin scales, lying closely compacted together, appear 
every year upon the stems, the boughs, and the branches ot 
trees. They contain the germs of the productions of the fol 
lowing years, and secure then from the severity of the seasons. 
These germs, and the scales which cover them, are called buds. 
The buds of the trees and shrubs of equinoctial countries, have 
few scales, as they are less needed for protection against in- 
buds ; they are the lungs of vegetables ; they absorb water and 
carbonic acid from the atmosphere, decompose them by the 
action of rays of light, and exhale or give out oxygen gas. 
They are tough and dry, soft and watery, in proportion as the 
fibrous or cellular tissue prevails. 
Yegetables, like animals, produce others of their kind, and 
thus perpetuate the works of creation. The organs essential to 
the perfection of plants, are the stamens and pistils. The pres- 
ence of a stamen and pistil constitutes what is called a perfect 
flower ; but, in general, these organs are surrounded with an 
3S. Tisane— Stem— Branches— Boughs— Herbs— Trees and Shrubs— BuJs— Leaves— EsBenlja] or 
gans. 
clemencies of weather. Leaves 
proceed from 
