Ernst Heinrich Philipp August Haeckel (16 February 1834 – 9 August 1919) was a German zoologist, artist, philosopher, and marine biologist, amongst other pursuits. His most famous research centered on the anatomy of radiolaria - microscopic protozoa with complex mineral shells - which, with other work, culminated in the beautifully illustrated Kunstformen dur Natur (Art forms of Nature). While not aboard HMS Challenger during her voyage (Haeckel was in residence as a professor at the University of Jena), he was enlisted to add his artistic skills to the Report, producing numerous drawings of medusae (jellyfish), radiolaria, keratosa (types of sponges), and siphonophores (communal organisms similar in appearance to some jellyfish). More than a few of his ideas have been debunked - in particular his anti-Darwinism and distasteful views on eugenics - but his talent for scientific drawing was undeniable.