p is 1/5 of r l ; c z goes 13 times into r c .
[Footnote: See Pl. XX where the text is also seen from lines 5-23.]
The movement of the arm (350-354).
350.
In the innermost bend of the joints of every limb the reliefs are converted into a hollow, and likewise every hollow of the innermost bends becomes a convexity when the limb is straightened to the utmost. And in this very great mistakes are often made by those who have insufficient knowledge and trust to their own invention and do not have recourse to the imitation of nature; and these variations occur more in the middle of the sides than in front, and more at the back than at the sides.
351.
When the arm is bent at an angle at the elbow, it will produce some angle; the