Histology of testis. Each testis is composed of a large number of seminiferous tubules surrounded by connective tissue in which are present numerous cells called interstitial cells or Leydig cells. The testis is covered by a layer of dense connective tissue called tunica albuginea. From it various septa radiate inward into the cavity of the testis dividing it into many lobules. The seminiferous tubules are coiled structures. Each tubule is lined by a layer of germinal epithelial cells. In between the germinal cells certain large cells called Sertoli cells are present. They are nutritive in function. The germinal epithelial cells give rise to sperms. They are in various stages of development like spermatogonia, primary spermatocytes, secondary spermatocytes and spermatids. The Leydig cells which he in connective tissue produce male sex hormone called testosterone.

 T.S. of Mammalian Testis.