During the second year of life, toddlers rapidly develop hand and finger skills. Drawing is a major accomplishment during this period, and two-year-olds will clumsily grasp crayons or pens and draw pictures using sweeping vertical, horizontal, and circular strokes.
Shelov, S. P. (Editor-in-Chief). (2004.) Caring for Your Baby and Young Child: Birth to Age 5. The American Association of Pediatrics. Revised edition. New York: Bantam Books.