Vermont phÅ“nix. [volume] (Brattleboro, Vt.) 1834-1955, 1882-05-05

The following by Col. W. S. Clark, recent
ly President of Amherst Agricultural College
in Massachusetts, will prove interesting to
our readers
In consideration of the subject of the circu.
lation of saps in the entire plant two topics
are involved about which there have been
much controversy and speculation, and too
little observation and true philosophy. The
first relates to the ascent of what is STYLED the
crude sap, which enters at the root and rises
against the force of gravitation to the top
most leaf of even the tallest tree. The other
has reference to the return of the so.called
elaborated sap from the leaf to the root, SO as
to complete trees circulation. Many have
said there is no such thing as a general circu-
lation of sap but no one doubts the fact of
an upward flow from the roots, and a vast
exhalation of water from the foliage during
the period when the vital forces of the plant
are active. 1t is universally admitted that
the cells containing chlorophyl are the organs
in which the elements of the carbohydrates
are combined, and from which, therefore,
they must pass by some channel to all other
parts of the plant, where either growth &C.
ours or amyloid substances are stored for
future uses. whether the albuminoids are
formed also in the cells of the leaf, or are the
result of combinations occurring in the cam
blum between the soluble carbo- ydrates and
the ingredients of the crude ascending sap, is
not certain, and has no necessary connection
with the question:
Investigation seems to demonstrate that the
cambium layer is the seat of life, and that
whenever the direct communication between
the root ard the foliage is cut off in this layer
during one entire season of growth, the
whole plant perishes. 1t has also been de-
termined by experiment that if several rings
OF bark be removed from growing shoot in
such manner that On one of the isolated
sections of bark there be no leaf, while leaves
remain on others above and below this, then
the leafless section will fail to make any
growth in any part All other sections, if
furnished with one or more healthy leaves.
will increase in thickness by the formation of
new leaves, of wood and bark. This seems
to prove that the material for growth is elab-
GRATED by the leaves, and is transmitted only
through the cambium and has no power of
penetrating the tissues of the wood.
The peculiar vital and organic power of the
cambium is remarkably illustrated in the
structure and growth of grated trees. Every
person is aware that pear trees are grown up
on ounce roots, and that they often bear
finer fruit than when cultivated as standards
This is doubtless owing to the fact that ounce
roots, being diminutiye, furnish less water to
the leaves, which thus elaborate a richer sap
and produce more perfectly developed wood
and fruit.
The apricot may be grated on the plum,
and the peach on the apricot, and the almond
on the peach, and thus we may produce a tree
with plum roots and almond leaves. The
wood, however, of the stem, will consist of
four distinct varieties, though formed from
one continuous cambium layer. Below the
almond wood and bark, then perfect apricot
wood and bark, and at the bottom perfect
plum wood and bark. In this curious instance
we see the intimate correspondence between
the bark and the leaf for if we should re-
move the almond branches we might cause
the several sorts of wood to develop buds and
leafy twigs, each of its own kind. Each sec
ton of the compound stem has its seat of life
in the cambium, and the cambium of each re-
produces cells of its own species out of
common nutrient fluid. Thus there is seen
to be flow of sap upward in the wood and
flow of organizablo material, essential to the
life of the plant, proceeding from the leaf to
the root, through the bark and cambium
layer. From this perfected sap the growth
OF the season is formed, and provision for the
beginning of the next seasons growth is also
stored up, commonly in the root
As the fact of rOotward flow of elaborated
sap is very generally denied at the present
time, it may be well to quote single line
from the edition published in 1870 Of the ad-
mirable textbook on botany, by the late Prof.
Henfrey, of London, which has been careful
ly revised by Dr. Masters. In reference to
the subject he says; "The evidence of a de-
scent of elaborated sap is overwhelming"