Otto Haeckel

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

Erich Heckel and Otto Mueller playing Chess, 1913 Anonymous

Prof. Haeckel Ernst Haeckel

Otto Lilienthal makes one of his last flights Anonymous

Octopuses. Gamochonia Ernst Haeckel

Portrait of Erich Heckel 1911 Ernst Ludwig Kirchner

Moths. Tineida Ernst Haeckel

Algae. Diatomea Ernst Haeckel

Portrait of Erich Heckel, 1910 Anonymous

Glass sponges. Hexactinellae Ernst Haeckel

Starfish and details of starfish anatomy. Ophiodea Ernst Haeckel

Fish. Teleostei Ernst Haeckel

Microorganisms. Phaeodaria Ernst Haeckel

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

Microorganisms. Flagellata Ernst Haeckel

Corals. Hexacoralla Ernst Haeckel

Portrait of Hendricks Haecks Nicolaas Verkolje

Microorganisms. Thalamophora Ernst Haeckel

Microorganisms. Thalamophora Ernst Haeckel

Otto Coke and Coal Hoist Elisha Kent Kane Wetherill

Algae in the genus Pediastrum. Melethallia Ernst Haeckel

Otto Lilienthal, German aeronaut, early 20th century Unknown

'Gamochonia' [octopus and squid] Adolf Giltsch

Microorganisms. Peridinea Ernst Haeckel

Ottokar Pays Homage to Rudolf, 1882 Anonymous

Geese Grazing near Rahlstedt Otto Speckter

Aquatic animals. Acanthophracta Ernst Haeckel

Portrait of Otto von Bismark Anonymous

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

The Stadtbahn Pavilion of the Vienna Underground Railway, design showing the exterior and a view of the railway platform, c.1894-97 Otto Wagner

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

Microorganisms. Rotatoria Ernst Haeckel

Sea urchins and sand dollars. Echinidea Ernst Haeckel

Corals. Tetracoralla Ernst Haeckel

Otto von Bismarck Carl Ludwig Friedrich Becker

Algae. Diatomea Ernst Haeckel