Leipzig, Leopold Voss, 1838. Two volumes in two. Folio (46.3 x 33.3 cm).Two title pages; , xviii, [iv], 548 pp; 64 engraved plates in fine, original hand-colouring. Uniform contemporary half morocco over pebbled boards. Spines with five raised bands; compartments with gilt floral vignettes, titles, and logos. Marbled endpapers.

Magnum opus, introducing the systematic study of micro-organisms, and the concept that they are neither animals nor plants, of the German zoologist, explorer, and microscopist Chistian Gottfried Ehrenberg (1795-1876). The fine plates are after original drawings by Ehrenberg himself, who was an accomplished artist. "Ehrenberg was the premier microscopist for most of the 19th century, famous in his time for drawing attention to microorganisms both living and fossil. Today he is credited as one of the founders of protozoology by authoring a "truly monumental monograph", his 1838 Die Infusionsthierschen als volkommene Organismen [this work]. The monograph included an "Atlas" of 64 hand-colored plates illustrating living microorganisms. The work has been described as "the most sumptuously illustrated classic of the field" (Churchill 1989). By the late 1830's, Ehrenberg had turned his attention to studies of the remains of microorganisms in atmospheric dust, soils, minerals and sediments. He was the first to systematically investigate the remains of microorganisms, shells, skeletons, etc., and today is credited as the "Founder of Micropaleontology" (Dolan). Provenance: very small circular stamp of the Quekett Microscopical Club on both titles; a few text page margins, and on plate versos (not shining through), "Presented by Mr [illegible]" (dated 1884); gilt Club logo on spines' foot. Extremities a bit dry and worn or scuffed. Scattered foxing to the text, however, mostly clean. Some plates with minute spotting, due to the paper quality. Very rare work, most copies with more serious paper or foxing problems than here, all considered this is a very good copy. Cat. BM(NH), p. 515; Churchill, F. B. (1989). The guts of the matter: infusoria from Ehrenberg to Bütschli: 1838-1876. In: Journal of the History of Biology, 22 pp. 189-213; Dolan, J. R. (2022) The Lesser-Known Scientific Art of Christian Gottfried Ehrenberg; Nissen ZBI, 1244.