Daily American organ. [volume] (Washington, D.C.) 1854-1856, 1855-01-15
AMERICAN ORGAN.
Lectures at the Smithsonian Institution.
REPORTED roR THE AMERICAN ORGAN

| REPORTED FOR THE AMERICAN ORGAN.
VEGETATION In ITS ORDINARY FORMS
| By PRor Asa GRAY, or HARVARD UsIyERsrTT,-
He recapitulated what he had advanced IN for
mer lectures, of the plan Of structure Of the plant
that II consists Of an axis growing in opposite di-
| rections that all which grows downward belongs
to the root whether 1t originates from the joint Of
| the stem in the embryo, or any succeeding joint
| underground or in the air; and that the decend-
ing axis, or the root, merely branches into smaller
| roots
But the ascending axis or the stem, consists 4
succession Of joints, one the top Of the other
and each bearing at its apex leaf, or pair Of
leaves; and each leaf producing just above the
axil bud, which usually develop into branch.
In all the varied forms Of perfect vegetation this
and this alone Is found; though it may under
forms which disguise Its real nature from the super
fetal observer. Though any one can see that the
stem Of a grass stalk Of an herb, or trunk or
! bough of tree, are the same organ under differ
ent forms, yet at first view, the stem branch is
not SO apparent in the tcndrl Of the grape vine,
the thorn Of the honey locust, the tendr Of the
strawberry.
! The subterranean forms of the stem are most
disguised all tl6 underground parts Of the plant
are not roots. The underground branches produce
roots; but the difference between them and roots
! is plainly manifest.
There are many familiar cases Of branches creep
ing on the ground, or bending down and taking
root as in the currant; but often branches start
beneath the surface run horizontally for a short
distance, and then at last rise in air; they
are not green, as the light cannot reach them,
and though they bear no real leaves, yet the bud
scales take their places. In this way roses, rasp-
berries, &C., spread by underground branches.
These illustrate the natural propagation by divis-
ion we facilitate the growth by seyering the root
In pieces and as each piece has one or more buds,
on becoming independent these buds sprout and
send stem into the air, while it also from the
under side strikes roots into the earth and perhaps
sends out other subtcranean branches. This large
ly subserves mans purposes, as in case of the po
tato; but becomes an annoyance to the farmer
when found in the form of the Canada thistle, or
the quick grass.
These plants are still more different to KILL when,
instead of expanding all the nutriment gathered in
the course Of season. they store it up in the root
as in the beet or turnip; in subteranean branches,
as in the Jerusalem artchoke, or in the extremity
of the underground branches, in tubers as in the
potato or in the bases OF leaves underground, as
In all bulbs. l &~ &~
Bulb-bearing plants make up large proportion.
1t Is asked, What is the design of this mode of
vegetationg
Plants are formed on the principle Of extension
of surface; as plants live on earth and air, the
more they extend their surface the moro of these
they obtain. This is fully realized in trees peren-
NAL and annual herbs. In bulbus and tuberous
plants, there is the same economy, with greater
degree of consolidation, which is admirably adapted
to the climate TO which they belong They con-
sttute provision against drought they are indi-
gcnous TO countries which have hot, dry seasons,
in which vegetation is often completely sus-
pended for want of moisture, as it is here during
the winter Though plants are always surrounded
by earth and air, yet water which is prime ne
cessity 10 vegetation may fail In this dry season,
ordinary vegetation is suspended the bulbs are at
rest rs completely as those Of the waterly in our
present frozen soil and their leaves have perished,
the bulb alone bears it we'll Its spherical form,
presenting the least possible surface for evapora-
ton, and It's structure consisting Of layer within
layer of feshy coats, the outermost dry, husky
and fibrous, and therefore the poorer conductor
Of heat, enables II to hold the moisture incorpor
ate with the nourishment essential TO its life, with
the greatest tcnacity till the dry has passed
| Then when the rain falls, flowers and foliage shoot
| forth from the buds, and desert Of burning sand
becomes gay with blossoms almost in q day.
Bulbs are equally adapted to our own or higher
attitudes, where the climate Is doubly extreme, and
vegetation first has TO undergo hot and dry sea-
son, and then an intense cold winter.
The same end Is brought about by concentrar
ton of the nutrment above ground, in either the
leaves or the stem This is seen In the cactus fam
/ lily, which will thrive in our dwellings during the
winter, when nearly all the moisture is dried out
of the air by the stoves and where other plants will
not grow.
He nov spoke of the inability Of the frigid zones
to produce ful-grown trees. Only those countries
| where rain falls throughout the year are forest
clad There is an equatorial belt in which the
| rains are equally distributed through the whole
year, and these regions, except where man has in
tcrfercd with them, are covered with unbrokon and
| uxuriant forests.
Now followed an analysis Of the leaf IL is an
expansion of the green bark of tho shoot support
ed by framework of woolly fbres filed with .
green pulp, and hollow ribs and veins, through which
circulates the sap. The green pulp Is essential TO
the digestion of the crude sap 1t consists OF min
ute wavy grains hcaped in clusters, or floating in
mucilage this Is all contained in cells
The epidermis or skin Of the leaf consists Of
compactly joined cells, sometimes in two or three
| layers In order to resist evaporation. ~ sF
The arrangement to permit and restrain evapo-
ration as Il Is necessary consists ofbrcathing pores
and are mostly on the under side ofthe leaf There
are great number Of these pores; for instance in
the leaf Of the apple, there are $4,000 to the
| square inch, or 100000 for each leaf
From the beautiful Illustrations accompanying
this lecture this, dry subject to some, was render
ed quite interesting, and the many explanations Of
various phenomena pervading the discourse, made
It improving even 70 those who had no interest in
| the abstract science
At the commencement of the lecture, Prof
| Henry announced, that, as much disturbance had
been caused by the conduct Of rude boys in future
| no boys would be admitted, unless accompanied by
some ono who would take care OF them or unless
they had permits, which could be obtained by ap-
| plication to him This was received by the audi
ence with continued applause II is a regulation
that has long been needed.
The Know-Nothings and Seward.
II the New York Herald is to be believed, says
the Richmond Post, the elements OF opposition
combined against Seward are likely to shake his
throne TO the very foundation So wen aware is
h;rr,aon tho danQer which he