This illustration is by Ernst Haeckel’s book “Kunstformen der Natur” [Artforms of Nature]published in 1904.
Ernst Haeckel (1834 – 1919), a German biologist, philosopher, physician, who discovered, described and named thousands of new species, mapped a genealogical tree relating all life forms, and coined many terms in biology, as well as the term "ecology". Haeckel traveled far and wide, from Sicily to Ceylon, to the North Sea, and beyond. Sketchpads and watercolors accompanied his microscope wherever he went. His on-the-spot drawings of deep-sea vegetation, aquatic creatures, frogs, birds, and higher animals were turned into more than 1,000 engravings.Kunstformen der Natur High resolution scans of all of the plates are available here. via siongchin