Wichita eagle., 1889-12-28
THE Oak LEAF.
Psculiarities Of II, Shape, Structure and
Uses Ably Discussed.

Pseuliarities of Il, Shape, Structure and
Uses Ably Discussed.
Sir John Lubbock read a paper On the
shape of the oak leaf before the British as
ISOLATION recently, il the course Of which he
Eaid:
We are so accustomed to the form of the
oak leaf that it does not stril1e US as any
thing peculiar, and comparatively few, per-
haps, have ever asked themselves why it
should be as it is. And yet it is peculiar. I'M
like that of any Of our forest trees and those
of the evergreen Oak SO abundant in hot
countries.
In botanical phsaseology, they are decidu-
GUS, oblong- oblanceolate, or oblong- elliptical,
simulated, with blunt lobes extending not
more than hallway 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 botan-
ical works which have consulted, they are
rarely symmetrical, the lObes of the two
sides not corresponding. 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 out
line.
do not know of any attempt to explain
this peculiar fern. 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 be-
tween the lobes may be of some advantage in
the manner suggested by Kerner, but great
ly doubt whether this is the main primary
explanation. That which suggest is as fol-
lows:
The leaves Of the evergreen oak are entire
and small in comparison with the English
oak.
During the winter and early spring they
are protected by a series of brown scales, i'll
side which they lie, and with which they
form the well known bases which are SO
familiar to US and which are both small and
short in proportion to the size of the leaves
themselves In cooler and moister regions,
on the contrary, there is, as we knew, a ten
dency for leaves to become larger and de-
ciduous. will not now enter into tine rea-
son for this; but the fact will not, probably,
be denied. These influences do not, how
ever, 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 re-
If, for instance, we compare the buds of the
oak and of the beech, we see that, while the
leaf of the oak is longer than that of the
beech, the bud of the oali is, on the contrary,
shorter than that Of the beech Under these
circumstances what must happen2 The leaf
grows and becomes longer than the bud. It
is therefore necessarily bent into a curve.
But an entire leaf, if thus thrown into a
curve would necessarily fall into folds, the
number being determined by the number Of
ribs or veins. For such folds, however, there
would be no room within the narrow limits
Of bud; or, rather, perhaps they would be
mconvenient, because they leave mere oriess
empty spaces.
This may be rendered more clear by taking
piece Of cloth or o. paper, folding it up and
then throwing it into a curve 1t will then
necessarily fall into one or more folds If it
were strengthened as an oak leaf is, by three
or four side ribs, there would be fold be-
tween each two ribs As matter of fact.
however, from the absence of space the MEM
brane where the field would be is not actually
developed. We may initiate this by remov-
ing them. If this he done, the result will be
the formation of stnuses 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 short
ness of the bud in comparison with the length
of the lssi. The young leaf is not only
curved; it is wrapped roand 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 tde other. The two SIDES Of the
leaf are, ia fact, differently situated, and
this, believe, accounts for the second point
namely, the want Of symmetry. The OBJ
long form is an advantage, from the way the
leaves diverge from the stalk In this man
ner the interesting pecuiarities of the oak
leaf may be accounted for.