When a tree is seen from below, the eye sees the top of it as placed within the circle made by its boughs[23].

Remember, O Painter! that the variety of depth of shade in any one particular species of tree is in proportion to the rarity or density of their branches.

[Footnote:  The two lower sketches on the left of Pl XXVIII, No. 3, refer to lines 21-23.  The upper sketch has apparently been effaced by Leonardo himself.]

The distribution of light and shade with reference to the position of the spectator (441-443).

441.

The shadows of trees placed in a landscape do not display themselves in the same position in the trees on the right hand and those on the left; still more so if the sun is to the right or left.  As is proved by the 4th which says:  Opaque bodies placed between the light and the eye display themselves entirely in shadow; and by the 5th:  The eye when placed between the opaque body and the light sees the opaque body entirely illuminated.  And by the 6th:  When the eye and the opaque body are placed between darkness and light, it will be seen half in shadow and half in light.

[Footnote:  See the figure on the right hand side of Pl.  XXVIII, No. 3.  The first five lines of the text are written below the diagram and above it are the last eight lines of the text, given as No. 461.]

442.

OF THE HERBS OF THE FIELD.

Of the plants which take a shadow from the plants which spring among them, those which are on this side [in front] of the shadow have the stems lighted up on a background of shadow, and the plants on which the shadows fall have their stems dark on a light background; that is on the background beyond the shadow.

OF TREES WHICH ARE BETWEEN THE EYE AND THE LIGHT.

Of the trees which are between the eye and the light the part in front will be light; but this light will be broken by the ramifications of transparent leaves—­being seen from the under side—­and lustrous leaves—­being seen from the upper side; and the background below and behind will be dark green, being in shadow from the front portion of the said tree.  This occurs in trees placed above the eye.

443.

FROM WHENCE TO DEPICT A LANDSCAPE

Landscapes should be represented so that the trees may be half in light and half in shadow; but it is better to do them when the sun is covered with clouds, for then the trees are lighted by the general light of the sky, and the general darkness of the earth.  And then they are darkest in certain parts in proportion as those parts are nearest to the middle of the tree and to the earth.

The effects of morning light (444-448).

444.

OF TREES TO THE SOUTH.

When the sun is in the east the trees to the South and to the North have almost as much light as shadow.  But a greater share of light in proportion as they lie to the West and a greater share of shadow in proportion as they lie to the East.