From the earliest civilisations, plants and animals have been portrayed as a means of understanding and recording the potential uses, such as their economic and healing properties. From the first illustrated  　 of medicinal plants, De Materia Medica by Dioscorides, in the first century through to the late fourteenth century the illustration of plants and animals changed very little. Woodcuts in instructional manuals and herbals were often repeatedly copied over the centuries, resulting in a loss of definition and accuracy so that they became little more than stylized decoration. With the growing  　 of copperplate engravings, the traditional use of woodcuts declined and the representation of plants and animals became more  　 . Then, with the emergence of artists such as Albrecht Durer and Leonardo Da Vinci, naturalists such as Otto Brunfels, Leonhard Fuchs in botany and Conrad Gesner and Ulisse Aldrovandi in zoology, nature began to be depicted in a more realistic style.   living plants or animals were observed directly and their likeness  　 onto paper or vellum.