the nude forms be broken by too many details and interrupted folds. How draperies should be drawn from nature: that is to say if youwant to represent woollen cloth draw the folds from that; and if it is to be silk, or fine cloth or coarse, or of linen or of crape, vary the folds in each and do not represent dresses, as many do, from models covered with paper or thin leather which will deceive you greatly.[Footnote: The little pen and ink drawing from Windsor (W. 102), given on Pl. XXVIII, No. 7, clearly illustrates the statement made
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at the beginning of this passage; the writing of the cipher 19 on the same page is in Leonardo's hand; the cipher 21 is certainly not.] VIII.
Botany for Painters and Elements of Landscape Painting.
The chapters composing this portion of the work consist of observations on Form, Light and Shade in Plants, and particularly in
Trees summed up in certain general rules by which the author intends to guide the artist in the pictorial representation of landscape.
With these the first principles of a Theory of Landscape painting are laid down--a theory as profoundly thought out in its main lines as it is lucidly worked out in its details. In reading these chapters the conviction is irresistible that such a Botany for painters is or ought to be of similar importance in the practice of painting as the principles of the Proportions and Movements of the human figure i. e. Anatomy for painters.
There can be no doubt that Leonardo, in laying down these rules, did not intend to write on Botany in the proper scientific sense-- his own researches on that subject have no place here; it need only be observed that they are easily distinguished by their character and contents from those which are here collected and arranged under the title 'Botany for painters'. In some cases where this division might appear doubtful,--as for instance in No. 402--the Painter is directly addressed and enjoined to take the rule to heart as of special importance in his art.
The original materials are principally derived from MS. G, in which we often find this subject treated on several pages in succession without any of that intermixture of other matters, which is so frequent in Leonardo's writings. This MS., too, is one of the latest; when it was written, the great painter was already more than sixty years of age, so we can scarcely doubt that he regarded all he wrote as his final views on the subject. And the same remark applies to the chapters from MSS. E and M which were also written between
1513--15.
For the sake of clearness, however, it has been desirable to sacrifice--with few exceptions--the original order of the passages as written, though it was with much reluctance and only after long hesitation that I resigned myself to this necessity. Nor do I mean
to impugn the logical connection of the author's ideas in his MS.; but it will be easily understood that the sequence of disconnected notes, as they occurred to Leonardo and were written down from time to time, might be hardly satisfactory as a systematic arrangement of his principles. The reader will find in the Appendix an exact account of the order of the chapters in the original MS. and from the data there given can restore them at will. As the materials are here arranged, the structure of the tree as regards the growth of the branches comes first (394-411) and then the insertion of the leaves on the stems (412-419). Then follow the laws of Light and Shade as applied, first, to the leaves (420-434), and, secondly, to the whole tree and to groups of trees (435-457). After the remarks
on the Light and Shade in landscapes generally (458-464), we find special observations on that of views of towns and buildings
(465-469). To the theory of Landscape Painting belong also the passages on the effect of Wind on Trees (470-473) and on the Light and Shade of Clouds (474-477), since we find in these certain comparisons with the effect of Light and Shade on Trees (e. g.: in No.
476, 4. 5; and No. 477, 9. 12). The chapters given in the Appendix Nos. 478 and 481 have hardly any connection with the subjects
previously treated.
Classification of trees.
393. TREES.
Small, lofty, straggling, thick, that is as to foliage, dark, light, russet, branched at the top; some directed towards the eye, some down-
wards; 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.
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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.
OF THE SCARS ON TREES.
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
