The Notebooks of Leonardo Da Vinci — Complete
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.
OF THE RAMIFICATIONS OF PLANTS.
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.
OF THE INSERTION OF THE BRANCHES ON PLANTS.
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.
A DESCRIPTION OF THE ELM.
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.
OF THE INSERTION OF THE LEAVES ON THE BRANCHES.
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.
416.
OF THE RAMIFICATIONS OF TREES AND THEIR FOLIAGE.
The ramifications of any tree, such as the elm, are wide and slender
after the manner of a hand with spread fingers, foreshortened. And
these are seen in the distribution [thus]: the lower portions are
seen from above; and those that are above are seen from below; and
those in the middle, some from below and some from above. The upper
part is the extreme [top] of this ramification and the middle
portion is more foreshortened than any other of those which are
turned with their tips towards you. And of those parts of the middle
of the height of the tree, the longest will be towards the top of
the tree and will produce a ramification like the foliage of the
common willow, which grows on the banks of rivers.
Other ramifications are spherical, as those of such trees as put
forth their shoots and leaves in the order of the sixth being placed
above the first. Others are thin and light like the willow and
others.
417.
You will see in the lower branches of the elder, which puts forth
leaves two and two placed crosswise [at right angles] one above
another, that if the stem rises straight up towards the sky this
order never fails; and its largest leaves are on the thickest part
of the stem and the smallest on the slenderest part, that is towards
the top. But, to return to the lower branches, I say that the leaves
on these are placed on them crosswise like [those on] the upper
branches; and as, by the law of all leaves, they are compelled to
turn their upper surface towards the sky to catch the dew at night,
it is necessary that those so placed should twist round and no
longer form a cross.
[Footnote: See Pl. XXVII, No. 5.]
418.
A leaf always turns its upper side towards the sky so that it may
the better receive, on all its surface, the dew which drops gently