Defined in the Oxford Dictionary as "mediaeval, moralizing treatises on beasts," bestiaries have in fact been made since earlier times. In the first century, Pliny's Natural History was based on his own perceptions and experiments, as well as on Aristotle’s History of Animals and popular beliefs of the period. Following this work and the Physiologus of the fifth century, bestiaries became popular in the Middle Ages and Renaissance. They were considered serious works of natural history that drew on visual observations, folklore, and moral allegories to study wildlife. Traditionally, bestiaries were profusely illustrated with drawings, prints and paintings. Artists such as Picasso and Toulouse-Lautrec continued the practice of making books on beasts in the twentieth century. Nova Scotia artist Cecil Day's An Atlantic Bestiary, a suite of 20 colour etchings of small animals coupled with local folk sayings, offers a contemporary take on this time-honored art form