The principal shadows on a face are generally cast by the eyebrows and the nose, and can be compared to a peg inserted in an egg-form with a grove cut above it. The under side of the jaws, below the lower lip, and under the ear-lobes are other shadow areas, depending on the direction of light. The more finished heads shown, are examples of these rules, and arrows indicate the direction from which the light is coming. Indicating detail in a shadow brings out the effect of reflected light as pictured in the head of the old lady with the bonnet.