The Notebooks of Leonardo Da Vinci (25 page)

Classification of trees.

393.

Small, lofty, straggling, thick, that is as to foliage, dark, light,
russet, branched at the top; some directed towards the eye, some
downwards; with white stems; this transparent in the air, that not;
some standing close together, some scattered.

The relative thickness of the branches to the trunk (393—396).

394.

All the branches of a tree at every stage of its height when put
together are equal in thickness to the trunk [below them].

All the branches of a water [course] at every stage of its course,
if they are of equal rapidity, are equal to the body of the main
stream.

395.

Every year when the boughs of a plant [or tree] have made an end of
maturing their growth, they will have made, when put together, a
thickness equal to that of the main stem; and at every stage of its
ramification you will find the thickness of the said main stem; as:
i k
,
g h
,
e f
,
c d
,
a b
, will always be equal to each
other; unless the tree is pollard—if so the rule does not hold
good.

All the branches have a direction which tends to the centre of the
tree
m
.

[Footnote: The two sketches of leafless trees one above another on
the left hand side of Pl. XXVII, No. 1, belong to this passage.]

396.

If the plant n grows to the thickness shown at m, its branches will
correspond [in thickness] to the junction a b in consequence of the
growth inside as well as outside.

The branches of trees or plants have a twist wherever a minor branch
is given off; and this giving off the branch forms a fork; this said
fork occurs between two angles of which the largest will be that
which is on the side of the larger branch, and in proportion, unless
accident has spoilt it.

[Footnote: The sketches illustrating this are on the right hand side
of PI. XXVII, No. I, and the text is also given there in facsimile.]

397.

There is no boss on branches which has not been produced by some
branch which has failed.

The lower shoots on the branches of trees grow more than the upper
ones and this occurs only because the sap that nourishes them, being
heavy, tends downwards more than upwards; and again, because those
[branches] which grow downwards turn away from the shade which
exists towards the centre of the plant. The older the branches are,
the greater is the difference between their upper and their lower
shoots and in those dating from the same year or epoch.

[Footnote: The sketch accompanying this in the MS. is so effaced
that an exact reproduction was impossible.]

398.

The scars on trees grow to a greater thickness than is required by
the sap of the limb which nourishes them.

399.

The plant which gives out the smallest ramifications will preserve
the straightest line in the course of its growth.

[Footnote: This passage is illustrated by two partly effaced
sketches. One of these closely resembles the lower one given under
No. 408, the other also represents short closely set boughs on an
upright trunk.]

400.

The beginning of the ramification [the shoot] always has the central
line [axis] of its thickness directed to the central line [axis] of
the plant itself.

401.

In starting from the main stem the branches always form a base with
a prominence as is shown at
a b c d
.

402.

When the branches which grow the second year above the branch of the
preceding year, are not of equal thickness above the antecedent
branches, but are on one side, then the vigour of the lower branch
is diverted to nourish the one above it, although it may be somewhat
on one side.

But if the ramifications are equal in their growth, the veins of the
main stem will be straight [parallel] and equidistant at every
degree of the height of the plant.

Wherefore, O Painter! you, who do not know these laws! in order to
escape the blame of those who understand them, it will be well that
you should represent every thing from nature, and not despise such
study as those do who work [only] for money.

The direction of growth (403-407).

403.

The plants which spread very much have the angles of the spaces
which divide their branches more obtuse in proportion as their point
of origin is lower down; that is nearer to the thickest and oldest
portion of the tree. Therefore in the youngest portions of the tree
the angles of ramification are more acute. [Footnote: Compare the
sketches on the lower portion of Pl. XXVII, No. 2.]

404.

The tips of the boughs of plants [and trees], unless they are borne
down by the weight of their fruits, turn towards the sky as much as
possible.

The upper side of their leaves is turned towards the sky that it may
receive the nourishment of the dew which falls at night.

The sun gives spirit and life to plants and the earth nourishes them
with moisture. [9] With regard to this I made the experiment of
leaving only one small root on a gourd and this I kept nourished
with water, and the gourd brought to perfection all the fruits it
could produce, which were about 60 gourds of the long kind, andi set
my mind diligently [to consider] this vitality and perceived that
the dews of night were what supplied it abundantly with moisture
through the insertion of its large leaves and gave nourishment to
the plant and its offspring—or the seeds which its offspring had
to produce—[21].

The rule of the leaves produced on the last shoot of the year will
be that they will grow in a contrary direction on the twin branches;
that is, that the insertion of the leaves turns round each branch in
such a way, as that the sixth leaf above is produced over the sixth
leaf below, and the way they turn is that if one turns towards its
companion to the right, the other turns to the left, the leaf
serving as the nourishing breast for the shoot or fruit which grows
the following year.

[Footnote: A French translation of lines 9-12 was given by M.
RAVAISSON in the
Gazette des Beaux Arts
, Oct. 1877; his paper also
contains some valuable information as to botanical science in the
ancient classical writers and at the time of the Renaissance.]

405.

The lowest branches of those trees which have large leaves and heavy
fruits, such as nut-trees, fig-trees and the like, always droop
towards the ground.

The branches always originate above [in the axis of] the leaves.

406.

The upper shoots of the lateral branches of plants lie closer to the
parent branch than the lower ones.

407.

The lowest branches, after they have formed the angle of their
separation from the parent stem, always bend downwards so as not to
crowd against the other branches which follow them on the same stem
and to be better able to take the air which nourishes them. As is
shown by the angle
b a c
; the branch
a c
after it has made the
corner of the angle
a c
bends downwards to
c d
and the lesser
shoot
c
dries up, being too thin.

The main branch always goes below, as is shown by the branch
f n
m
, which does not go to
f n o
.

The forms of trees (408—411).

408.

The elm always gives a greater length to the last branches of the
year's growth than to the lower ones; and Nature does this because
the highest branches are those which have to add to the size of the
tree; and those at the bottom must get dry because they grow in the
shade and their growth would be an impediment to the entrance of the
solar rays and the air among the main branches of the tree.

The main branches of the lower part bend down more than those above,
so as to be more oblique than those upper ones, and also because
they are larger and older.

409.

In general almost all the upright portions of trees curve somewhat
turning the convexity towards the South; and their branches are
longer and thicker and more abundant towards the South than towards
the North. And this occurs because the sun draws the sap towards
that surface of the tree which is nearest to it.

And this may be observed if the sun is not screened off by other
plants.

410.

The cherry-tree is of the character of the fir tree as regards its
ramification placed in stages round its main stem; and its branches
spring, 4 or five or 6 [together] opposite each other; and the tips
of the topmost shoots form a pyramid from the middle upwards; and
the walnut and oak form a hemisphere from the middle upwards.

411.

The bough of the walnut which is only hit and beaten when it has
brought to perfection…

[Footnote: The end of the text and the sketch in red chalk belonging
to it, are entirely effaced.]

The insertion of the leaves (412—419).

412.

Such as the growth of the ramification of plants is on their
principal branches, so is that of the leaves on the shoots of the
same plant. These leaves have [Footnote 6:
Quattro modi
(four
modes). Only three are described in the text, the fourth is only
suggested by a sketch.

This passage occurs in MANZI'S edition of the Trattato, p. 399, but
without the sketches and the text is mutilated in an important part.
The whole passage has been commented on, from MANZI'S version, in
Part I of the
Nuovo Giornale Botanico Italiano
, by Prof. G.
UZIELLI (Florence 1869, Vol. I). He remarks as to the 'four modes':
"
Leonardo, come si vede nelle linie sententi da solo tre esempli.
Questa ed altre inessattezze fanno desiderare, sia esaminato di
nuovo il manoscritto Vaticano
". This has since been done by D.
KNAPP of Tubingen, and his accurate copy has been published by H.
LUDWIG, the painter. The passage in question occurs in his edition
as No. 833; and there also the drawings are wanting. The space for
them has been left vacant, but in the Vatican copy '
niente
' has
been written on the margin; and in it, as well as in LUDWIG'S and
MANZI'S edition, the text is mutilated.] four modes of growing one
above another. The first, which is the most general, is that the
sixth always originates over the sixth below [Footnote 8:
la sesta
di sotto. "Disposizione 2/5 o 1/5. Leonardo osservo probabilmente
soltanto la prima"
(UZIELLl).]; the second is that two third ones
above are over the two third ones below [Footnote 10:
terze di
sotto: "Intende qui senza dubbio parlare di foglie decussate, in cui
il terzo verticello e nel piano del primo"
(UZIELLI).]; and the
third way is that the third above is over the third below [Footnote
11: 3a
di sotto: "Disposizione 1/2"
(UZIELLI).].

[Footnote: See the four sketches on the upper portion of the page
reproduced as fig. 2 on P1. XXVII.]

413.

The ramification of the elm has the largest branch at the top. The
first and the last but one are smaller, when the main trunk is
straight.

The space between the insertion of one leaf to the rest is half the
extreme length of the leaf or somewhat less, for the leaves are at
an interval which is about the 3rd of the width of the leaf.

The elm has more leaves near the top of the boughs than at the base;
and the broad [surface] of the leaves varies little as to [angle
and] aspect.

[Footnote: See Pl. XXVII, No. 3. Above the sketch and close under
the number of the page is the word '
olmo
' (elm).]

414.

In the walnut tree the leaves which are distributed on the shoots of
this year are further apart from each other and more numerous in
proportion as the branch from which this shoot springs is a young
one. And they are inserted more closely and less in number when the
shoot that bears them springs from an old branch. Its fruits are
borne at the ends of the shoots. And its largest boughs are the
lowest on the boughs they spring from. And this arises from the
weight of its sap which is more apt to descend than to rise, and
consequently the branches which spring from them and rise towards
the sky are small and slender [20]; and when the shoot turns towards
the sky its leaves spread out from it [at an angle] with an equal
distribution of their tips; and if the shoot turns to the horizon
the leaves lie flat; and this arises from the fact that leaves
without exception, turn their underside to the earth [29].

The shoots are smaller in proportion as they spring nearer to the
base of the bough they spring from.

[Footnote: See the two sketches on Pl XXVII, No. 4. The second
refers to the passage lines 20-30.]

415.

The thickness of a branch never diminishes within the space between
one leaf and the next excepting by so much as the thickness of the
bud which is above the leaf and this thickness is taken off from the
branch above [the node] as far as the next leaf.

Nature has so placed the leaves of the latest shoots of many plants
that the sixth leaf is always above the first, and so on in
succession, if the rule is not [accidentally] interfered with; and
this occurs for two useful ends in the plant: First that as the
shoot and the fruit of the following year spring from the bud or eye
which lies above and in close contact with the insertion of the leaf
[in the axil], the water which falls upon the shoot can run down to
nourish the bud, by the drop being caught in the hollow [axil] at
the insertion of the leaf. And the second advantage is, that as
these shoots develop in the following year one will not cover the
next below, since the 5 come forth on five different sides; and the
sixth which is above the first is at some distance.