Otto Haeckel

Washing-up at a juvenile summer holiday camp, Germany Otto Haeckel

Erich Heckel and Otto Mueller playing Chess, 1913 Anonymous

Octopuses. Gamochonia Ernst Haeckel

The Children of Martin Anton Heckscher: Johann Gustav Wilhelm Moritz…, 1805 Johann Heinrich Wilhelm Tischbein

Prof. Haeckel Ernst Haeckel

Otto Lilienthal makes one of his last flights Anonymous

Otto Lilienthal, German aeronaut, early 20th century Unknown

Otto von Guericke, German inventor, engineer and physicist, 1672 Unknown

Glass sponges. Hexactinellae Ernst Haeckel

Hummingbirds. Trochilidae Ernst Haeckel

Fish. Teleostei Ernst Haeckel

Moths. Tineida Ernst Haeckel

Entrance of Otto of Bavaria into Nauplia, 6th February 1833 German School

'Gamochonia' [octopus and squid] Adolf Giltsch

Glass sponges. Hexactinellae Ernst Haeckel

'Hexastylus' E Giltsch

Portrait of Physicist Otto von Guericke Anonymous

Starfish and details of starfish anatomy. Ophiodea Ernst Haeckel

Boxfishes. Ostraciontes Ernst Haeckel

Portrait of Otto von Bismarck in Hunting Clothes with his Dog and a Dead Pheasant, 1897 Otto Johann Heinrich Heyden

Microorganisms. Rotatoria Ernst Haeckel

Algae. Diatomea Ernst Haeckel

Otto Erich Hartleben German School

Ernest Haekel Anonymous

Portrait of Otto Brahe, Captain of a Company of Danes to Repartition Zealand, Entered Service of Brandenburg in 1610 Anonymous

Microorganisms. Thalamophora Ernst Haeckel

Otto I Submitting to Berenger II and the Triumph of Italy German School

Portrait of Otto von Bismark Anonymous

Microorganisms. Flagellata Ernst Haeckel

Microorganisms. Flagellata Ernst Haeckel

Glass sponges. Hexactinellae Ernst Haeckel

Microorganisms. Phaeodaria Ernst Haeckel

Corals. Hexacoralla Ernst Haeckel

Fungi. Ascomycetes Ernst Haeckel

Otto Salzer, 1905(?) Unknown

Microorganisms. Peridinea Ernst Haeckel