The better we understand the skeleton, and what is generally understood as "artists' anatomy," the greater will be our power of constructing the human figure, and realising the subtleties of form.
In our initial sketches for compositions, when memory has to take the place of the living model, we rely to a great extent on our anatomical knowledge for the suggestion of action and form generally. And again it adds materially to our faculties for self-criticism, which, like a sense of humour, is often, nearly always, our salvation.
There are good books and good lecturers to which, and to whom, the student must look for advice and knowledge in that very necessary branch of science.
The bones are your architectural beams. Study the skull, and look for the bone forms in every head you draw. You will feel that the skin is more tightly drawn, and therefore of a different texture, over bone foundations, and more fleshy where free.
Equally, the muscles over the framework of the ribs follow the inclination of that practically fixed " cage," leaving the abdominal muscles freer play.
Note the shape and movements of the collarbones and of the scapulae.
Compare always the inclination of the ilium with the cage of ribs, and study the knee-bones, which are so near the surface. Note that the outer ankle-bone is placed lower than the inner, and so forth.
To most of these points I shall have to direct your attention in the subsequent lessons on the construction of the human figure.