80 [ Eep. No. 564. ] 
fibres called Common Hemp, are both obtained from dried barks of a retic¬ 
ulated structure. 
The fine foliaceous fibres called tropical flax, and the coarse foliaceous 
.fibres called Sisal hemp, are both obtained from green leaves with longi¬ 
tudinal and parallel veins. 
The common cortical fibres called flax and hemp, are separated by te¬ 
dious, tardy, laborious, complicated, and frequently sickly processes. 
The common foliaceous fibres, which are superior substitutes for both, 
are separated by a simple, speedy, and healthy process. The plants which 
furnish common flax and hemp are annuals, which exhaust the richest 
soils. The plants which yield the foliaceous substitutes are perennials, 
and enrich the poorest soils. Finally, the fibrous-leaved plants are prin¬ 
cipally composed of great masses of leaves alone ; and it is a general fact, 
that the greater the size and the greater the number of leaves of plants, 
the more they derive their nourishment from the atmosphere, and the less 
do they depend on the earth 
H. R 
riBROUS-LEAVED PLANTS. 
All flowering plants are divided, by botanists, into two great classes, 
called Monocotyledons and Dicotyledons, from peculiar characters of their 
seeds ; or Endogens and Exogens, from peculiar characters of their stems; 
and they might be called by equally significant names from the peculiar 
characters of their leaves. The stems of Endogenous plants are properly 
stalks, cylindrical and undivided; the stems of Exogenous plants are pro¬ 
perly trunks, conical and branched. A section of a stalk exhibits a 
homogeneous surface of porous materials, softest at the centre, hardest at 
the circumference, and without bark. If there be any appearance of a 
proper bark, it is made by the united bases of the adherent leaves; e. g. 
a Palm. A section of a trunk exhibits concentric circles of bark and 
wood, hardest at the heart, softest at the circumference, and with medul¬ 
lary rays from the central pith to the young external wood; e. g. an 
Oak. Hence plants of the first class may be at once known by the ab¬ 
sence of bark from their stalks ; and plants of the second class are always 
known by presence of bark on their trunks. 
Of Endogenous plants, the leaves have mostly parallel veins, and are 
generally adherent to the.stalk. Examples: Indian Corn, Lily, Flag, Flax- 
lily, Bear-grass, Palmetto, Spanish bayonet. Pine-apples. 
Of Exogenous plants, the leaves have mostly branching and reticulated 
veins, always articulated with the stem, and hence spontaneously falling. 
Examples : Chesnut, Currant, Flax and Hemp. 
The Endogenous differ from the Exogenous plants, in their geographical 
distribution, as well as in their structure. 
In the Equinoctial regions, the- Endogenous plants form about 17 per 
cent, of the flowering plants. In the Variable zone, between 36 and 52, 
about 25 per cent.; and towards the Polar circles, about 33 per cent. The 
most important substances which they produce, are farinaceous and sac¬ 
charine materials, and foliaceous fibres. The smaller grasses which 
■yield wheat, &c. in terminal heads of grain ; the large grass which yields 
maize in lateral ears of corn; and the equally large grass which yields 
