This filtrate flows through the mesonephric tubule and is drained into the continuation of the pronephric duct, now called the mesonephric duct or Wolffian duct. The nephrotomes of the pronephros degenerate while the mesonephric duct extends towards the most caudal end of the embryo, ultimately attaching to the cloaca. The mammalian mesonephros is similar to the kidneys of aquatic amphibians and fishes.
Filtrate passes through the mesonephric tubule, which connects to the pronephric duct, now called the mesonephric duct or Wolffian duct.  The pronephros's nephrotomes degenerate while the mesonephric duct extends towards the tail end of the embryo and eventually joins the cloaca. The mammalian mesonephros resembles the kidneys found in aquatic amphibians and fish.