What is "mesonephros"

Mesonephros \Mes`o*neph"ros\, n. [NL., fr. Gr. me`sos middle + nefro`s kidney.] (Anat.) The middle one of the three pairs of embryonic renal organs developed in most vertebrates; the Wolffian body.

n. (context biology English) The second of the three excretory organs of the developing embryo; the Wolffian body

The mesonephros is one of three excretory organs that develop in vertebrates. It serves as the main excretory organ of aquatic vertebrates and as a temporary kidney in reptiles, birds, and mammals. The mesonephros is included in the Wolffian body after Caspar Friedrich Wolff who described it in 1759. (The Wolffian body is composed of : mesonephros + paramesonephrotic blastema)