Pavia, Galeazzi, 1819. Large 4to (30.0 x 22.4 cm). Title page, [iv], 119 pp., four lithographed plates, of which two in double-suite: line drawings and lithographs, (partly) hand-coloured by the second author. Late 19th-century pebbled morocco over marbled boards. Spine with polished morocco label with gilt title. Marbled endpapers, speckled edges.

The rare first (co)authored work by the Italian zoologist and anatomist Mauro Rusconi (1776-1849), who studied with George Cuvier in Paris, and made many new discoveries in the field of embryology, based on his studies of amphibians. "Mauro Rusconi was an Italian embryologist who studied the development of amphibians and fishes. Rusconi was born in Pavia and became a pupil of Spallanzani. In a famous paper, Del Proteo anguino di Laurenti (1819), Rusconi demonstrated that the olm ( Proteus) is an adult animal and not a larval form that maintains gills during development. Some of Rusconi's other research concerned the reproduction of the salamander and the artificial insemination of fish. His most important embryological studies were on the development of the frog's egg, in which he observed and correctly interpreted the process of segmentation, the first divisions of the egg. The Institut de France gave Rusconi a gold medal for science in 1831" (socialarchive, internet site). The olm, Proteus anguinus Laurenti, 1768, is illustrated with very precise and detailed drawings, partly in line drawings and "normal" drawings, in order to show various anatomical and morphological aspects within the same specimen of this enigmatic species from the western Balkans. The beauty of these illustrations shows that Rusconi was both a fine zoologist and an artist. His co-author, Pietro Configliachi (1777-1844), was the successor of Alessandro Volta as professor of physics at the University of Padua. Although Configliachi is listed as first author on the title page, this work is usually attributed to Rusconi and Configliachi. The rarity of this and most other works by Rusconi is underscored by Wilhelm Junk in his Rara: "...alle, wissenschaftlich so grundgelegen Werke R.'s [sind] von einer solchen Seltenheit...dass sie als unauffindbar gelten können. Keines - mit Ausnahme der ersten - is nämlich (ganz unbegreiflicherweise) in einer höheren Auflage als 100, einzige sogar bloss 25 Exemplaren gedruckt. So ist auch der Preis eines jeden Werkes, wenn wirklich eines einmal auftaucht, trotz des geringen Umfanges 100 bis 200 M[ar]k". With the fine, pictorial and herpetological bookplate of Gaston François de Witte (1897-1980), Ex Africa semper aliquid novi, with an African landscape and chamaeleon. As Adler notes, he was a "specialist on the herpetology of Central Africa", and a protégé of the great Belgian/British herpetologist George Boulenger. De Witte's stamp in the top margin of the half-title. Light creasing to a few plate margins. Some, mostly light, foxing throughout. Still a very good copy in an attractive binding. Adler I, p. 122 (for De Witte); Adler II, pp. 44-46 (for Rusconi); Junk, Rara, p. 156; Nissen ZBI, 940.