though a drawing in black chalk, at Windsor, of a man on horseback (PI.  LXXIII) may perhaps be a reminiscence of the statue of Marcus Aurelius at Rome.  It seems to me that the drapery in a pen and ink drawing of a bust, also at Windsor, has been borrowed from an antique model (Pl.  XXX).  G. G. Rossi has, I believe, correctly interpreted Leonardo’s feeling towards the antique in the following note on this passage in manzi’s edition, p. 501:  “Sappiamo dalla storia, che i valorosi artisti Toscani dell’eta dell’oro dell’arte studiarono sugli antichi marmi raccolti dal Magnifico LORENZO DE’ MEDICI.  Pare che il Vinci a tali monumenti non si accostasse.  Quest’ uomo sempre riconosce per maestra la natura, e questo principio lo stringeva alla sola imitazione di essa”—­Compare No. 10, 26—­28 footnote.]

The necessity of anatomical knowledge (488. 489).

488.

OF PAINTING.

It is indispensable to a Painter who would be thoroughly familiar with the limbs in all the positions and actions of which they are capable, in the nude, to know the anatomy of the sinews, bones, muscles and tendons so that, in their various movements and exertions, he may know which nerve or muscle is the cause of each movement and show those only as prominent and thickened, and not the others all over [the limb], as many do who, to seem great draughtsmen, draw their nude figures looking like wood, devoid of grace; so that you would think you were looking at a sack of walnuts rather than the human form, or a bundle of radishes rather than the muscles of figures.

489.

HOW IT IS NECESSARY TO A PAINTER THAT HE SHOULD KNOW THE INTRINSIC
FORMS [STRUCTURE] OF MAN.

The painter who is familiar with the nature of the sinews, muscles, and tendons, will know very well, in giving movement to a limb, how many and which sinews cause it; and which muscle, by swelling, causes the contraction of that sinew; and which sinews, expanded into the thinnest cartilage, surround and support the said muscle.  Thus he will variously and constantly demonstrate the different muscles by means of the various attitudes of his figures, and will not do, as many who, in a variety of movements, still display the very same things [modelling] in the arms, back, breast and legs.  And these things are not to be regarded as minor faults.

How to acquire practice.

490.

OF STUDY AND THE ORDER OF STUDY.

I say that first you ought to learn the limbs and their mechanism, and having this knowledge, their actions should come next, according to the circumstances in which they occur in man.  And thirdly to compose subjects, the studies for which should be taken from natural actions and made from time to time, as circumstances allow; and pay attention to them in the streets and piazze and fields, and note them down with a brief indication of the forms; [Footnote 5:  Lines 5-7 explained by the lower portion of the sketch