Ernst Haeckel was a professor of zoology in Germany from 1865 until 1909, who occasionally stooped to a bit of skullduggery to prove his theories. However the real area in which he stands out for me is his superb illustrations he created to illustrate his theories and work.
The published artwork of Haeckel includes over 100 detailed, multi-colour illustrations of animals and sea creatures that are extraordinary in their attention to detail. In a time before the camera was used to record detail we had Haeckel!
Jellyfish have never looked so good! Even though I am always impressed with the real thing, these just take my breath away!