The arm and head.

344.

From b to a is one head, as well as from c to a and this happens when the elbow forms a right angle.

[Footnote:  See Pl.  XLI, No. 1.]

Proportions of the arm (345-349).

345.

From the tip of the longest finger of the hand to the shoulder joint is four hands or, if you will, four faces.

a b c are equal and each interval is 2 heads.

[Footnote:  Lines 1-3 are given on Pl.  XV below the front view of the leg; lines 4 and 5 are below again, on the left side.  The lettering refers to the bent arm near the text.]

346.

The hand from the longest finger to the wrist joint goes 4 times from the tip of the longest finger to the shoulder joint.

347.

a b c are equal to each other and to the foot and to the space between the nipple and the navel d e will be the third part of the whole man.

f g is the fourth part of a man and is equal to g h and measures a cubit.

[Footnote:  See Pl.  XIX, No. 1. 1. mamolino (=_bambino_, little child) may mean here the navel.]

348.

a b goes 4 times into a c and 9 into a m.  The greatest thickness of the arm between the elbow and the hand goes 6 times into a m and is equal to r f.  The greatest thickness of the arm between the shoulder and the elbow goes 4 times into c m, and is equal to h n g.  The smallest thickness of the arm above the elbow x y is not the base of a square, but is equal to half the space h 3 which is found between the inner joint of the arm and the wrist joint.

[11]The width of the wrist goes 12 times into the whole arm; that is from the tip of the fingers to the shoulder joint; that is 3 times into the hand and 9 into the arm.

The arm when bent is 4 heads.

The arm from the shoulder to the elbow in bending increases in length, that is in the length from the shoulder to the elbow, and this increase is equal to the thickness of the arm at the wrist when seen in profile.  And the space between the bottom of the chin and the parting of the lips, is equal to the thickness of the 2 middle fingers, and to the width of the mouth and to the space between the roots of the hair on the forehead and the top of the head [Footnote:  Queste cose.  This passage seems to have been written on purpose to rectify the foregoing lines.  The error is explained by the accompanying sketch of the bones of the arm.].  All these distances are equal to each other, but they are not equal to the above-mentioned increase in the arm.

The arm between the elbow and wrist never increases by being bent or extended.

The arm, from the shoulder to the inner joint when extended.