Gonotomes

the segmented areas of the middle germ layer (the mesoderm)—the inner walls of the stems of the somites in the animal embryo.

The gonotomes are converted in the course of development to the genital ridges, which form the stroma of the gonads (mainly their cortical layer); the primary sex cells in the majority of animals originate outside the somites of the gonads in connection with the inner germ layer (the en-doderm) and later migrate to the genital ridges.