This is Ernst Haeckel

Canvas paintings by Ernst Haeckel (1834-1919 in Jena). Haeckel was not only a very talented draughtsman, but also a physician, zoologist, philosopher and great free thinker. He received recognition from Charles Darwin, among others. His works from "Art Forms of Nature" are fantastically detailed illustrations, which give any room an extravagance. Especially popular were the portraits of plankton organisms and jellyfish.