I have been reading this beautiful book. It is an historical overview of scientific illustrators between the late 1400s and the mid-1700s. This book is filled with illustrations of plants and animals by many different illustrators of these time periods and there are more in depth histories of Alexander Marshal, Maria Sibylla Merian and Mark Catesby with a chapter in the beginning on Leondardo da Vinci with many of his beautiful drawings.
My favorites are the illustrations of Maria Sibylla Merian (the late 15th century), she lived and worked in a time when it was rare for a woman to have a career and travel alone to exotic destinations. Her paintings of insects and plants are just gorgeous. I love the colors and textures on her illustration of the caiman.