Woodville Republican., 1889-12-28
LIE OAK TREEs Lac.
Some Of the PecuIIarIties Of its shape
Structure and Uses.


Some Of the PeculIaritles Of its shape,
Structure and Uses.
Sir John Labbock read paper on the
shape Of the oak leaf, before the British
Association recently, in the course Of
which he said:
"We are so accustomed to the form Of
the oak leaf that it does not strike us as
any thing peculiar, and comparatively
few perhaps have ever asked themselves
why it should be as it is. And yet it is
peculiar, unlike that Of any of our for
est trees, and those Of tho evergreen oak
so abundant in hot countries. In botan-
ical phraseologY, they are deciduous, OBJ
long-oblanceolate, or oblong-elliptical,
sinuated, with blunt lobes extending not
more than halfway down to the mid-rib.
The sinus between the lobes is generally
rounded off at the bottom. Again,
though have not found this mentioned
in the botanical works which | have
consulted, they are rarely symmetrical,
the lobes of the two sides not CORE
spending. The three points, then,
which give the oak leaf its peculiar form
are: first, the deep rounded sinuses,
second, the want of symmetry of the two
sides; third, the oblong or oblanceolate
outline.
81 do not know of any attempt to ex.
plain this peculiar form. AS regards
the sinuses, Kerner suggests that they
are intended to permit the passage of
light to the lower leaves. would not
deny that the space between the lobes
may be of some advantage in the man.
ner suggested by Kerner, but greatly
doubt whether this is the main primary
explanation. That which l would sug-
gest is as follows: The leaves of the
evergreen oaks are entire and small in
comparison with those Of the English
oak. During the winter and early
spring they are protected by series ct
brown scales, inside which they lie, and
with which they form the well-known
basis which are so familiar to us and
which are both small and short in pro-
portion to the size of the leaves them
selves. In cooler and moist regions, on
the contrary, there is, as we
know tendency for leaves to
become larger and deciduous. l will
not now enter into the reason for this:
but the fact will not, probably be de-
MED These influences do not, however,
affect the outer scales, which remain as
before without any increase of size.
But as the leaves have increased in size,
and the scales have not, the leaves can
no longer retain their original arrange
mentin the bud. If, for instance, We com
pare the buds of the oak and of the beech,
we see that, while the leaf of the oak
is no longer than that of the beech, the
bud of the oak is on the contrary, shorter
than that of the beech. Under these
circumstances, what must happen? The
leaf grows and becomes longer than the
bud. 1t is, therefore, necessarily bent
into a curve. But an entire leaf, if thus
thrown into curve, would necessarily
fall into folds, the number being deter
mined by the number of ribs or veins.
For such folds, however, there would be
no room within the narrow limits of a
bud, or rather, perhaps, they would be
inconvenient, because they leave more
or less empty spaces.
"This may be rendered more clear by
taking piece Of cloth or of paper, fold
ing it up, and then throwing it into a
curve 1t will then necessarily fall into
one or more folds. If it were strength
ened as an oak leaf is, by three or four
side ribs, there would be fold between
each two ribs. As matter of fact, how
ever, from the absence of space the
membrane, where the fold would be, is
not actually developed. We may imi-
tate this by removing them. If this be
done, the result will be the formation
of sinuses rounded at the base closely
resembling those so characteristic of the
oak leaf. These sinuses are due then,
as believe, to the curvature Of the leaf
owing to the shortness of the bud
in comparison with the length of the
leaf. The young leaf is not only curved,
it is wrapped round the interior leaves.
The result of this is that one side of the
leaf is folded within the other; the one,
therefore, being on the outer side, has
more space than the other. The two
sides of the leaf are, in fact, differently
situated, and this, / believe, accounts
for the second point-namely, the want
of symmetry. The oblong form is an
advantage, from the way the leaves di-
verge from the stalk. In this manner
the interesting peculiarities of the oak
leaf may be accounted for"