The second of the three excretory organs that develop in a vertebrate embryo, becoming the functioning kidney in fish and amphibians but replaced by the metanephros in higher vertebrates.
The excretory organ serving as the adult kidney of fishes and amphibians and as the embryonic kidney of higher vertebrates: the mesonephros and its duct develop into the epididymis and vas deferens in higher vertebrates.
The second of the three excretory organs that develop in a vertebrate embryo, becoming the functioning kidney in fish and amphibians but replaced by the metanephros in birds, reptiles, and mammals.
American Heritage Dictionary of the English Language, 5th Edition
Mesonephros Sentence Examples
The more complete replacements, such as the nephridia of the genital segment of Tubifex by a subsequently formed genital duct, may be compared with the succession of the nesonephros to the pronephros in vertebrates, and of the metanephros to the mesonephros in the higher vertebrates..
From the adjacent mesonephros cords of cells grow into the attached part of the genital ridge, or testis, as it now is, and from these the rete testis is developed.
Recent research, however, points to these cords of the rete testis et ovarii as being derived from the coelomic epithelium instead of from the mesonephros.
Lying dorsal to the genital ridge in the intermediate cell mass is the mesonephros, consisting FIG.