Of composing historical pictures. Of not considering the limbs in
the figures in historical pictures; as many do who, in the wish to
represent the whole of a figure, spoil their compositions. And when
you place one figure behind another take care to draw the whole of
it so that the limbs which come in front of the nearer figures may
stand out in their natural size and place.

How to represent the differences of age and sex (582-583).