wikipedia: "Ernst Heinrich Philipp August Haeckel (February 16, 1834 – August 9, 1919), was an eminent German biologist [...] and artist who discovered, described and named thousands of new species, mapped a genealogical tree relating all life forms, and coined many terms in biology, including phylum, phylogeny, ecology and the kingdom Protista. Read on
He is best known for his book Art Forms of Nature. "Originally published in sets of ten between 1899 and 1904 and as a complete volume in 1904, it consists of 100 prints of various organisms, many of which were first described by Haeckel himself. Over the course of his career, over 1000 engravings were produced based on Haeckel's sketches and watercolors." Read on