Many of you may be familiar with Ernst Haeckel. A contemporary and supporter of Darwin and a controversial figure (what forward thinker isn't controversial?). He is a noted 19th Century Scientist and as you can see insanely talented as an artist - his illustrations are mind boggling.
I have an old copy of the artforms in nature, in german; I just ordered a "new" book from Prestel about Haeckel and his work.
If you are not familiar with him, check out the links below and be prepared to be impressed, wowed and amazed!