402

The law of proportion in the growth of the branches.

WHY, VERY FREQUENTLY, TIMBER HAS VEINS THAT ARE NOT STRAIGHT.

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.

Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.

VII * X
Notebooks of Leonoardo da Vinci
VIII: Botany for Painters and Elements of Landscape Painting.
. . .
Classification of trees.
393
The relative thickness of the branches to the trunk.
394,
395
The law of proportion in the growth of the branches.
396,
397,
398,
399,
400,
401,
402
The direction of growth.
403,
404,
405,
406,
407
The forms of trees.
408,
409,
410,
411
The insertion of the leaves.
412,
413,
414,
415,
416,
417,
418,
419
Light on branches and leaves.
420,
421,
422
. . .