Mesonephric tubules

Mesonephric tubules are genital ridges that are next to the mesonephros.

In males, some of the mesonephric kidney tubules, instead of being used to filter blood like the rest, "grow" over to the developing testes, penetrate them, and become connected to the seminiferous tubules of the testes. They also form the epididymis and the paradidymis.