AbstractIn the testes of man and some other mammals a structure is formed during reproductive age, designated a “receptacle”. This structure which is not present during infancy represents the first communication of the seminiferous tubules to an extragonadal organ the rete “organ,” the receptacles received the mature spermatozoa which later are transported to the mesonephric excretory duct through the rete tubules. The receptacles are the distal end of the rete tubules and are considered as coelomic funnels.The epithelium of the receptacles, the tubuli recti and rete tubules is identical in infantile and mature testes and of a different type than the epithelium of the seminiferous tubules.The receptacle consists of a distal dilatation of the tubuli recti in which the seminiferous tubule invaginates following the ruptures of their walls. Identical receptacles are present in man, horse (Equus caballus), armadillo (Dasypus novemcinctus mexicanus), white‐tailed deer (Odocoileus virginianus), dog (Canis familiaris), cat (Felix domesticus), hamster (mesocricetus auratus) and woodhuck (Marmota monax). In the mule (sterile offspring of a mare and a jackass) the receptacles lack communications.The presence of mature spermatozoa is believed to be the proper stimulus for the formation of the receptacles which established the communications between the seminiferous tubules and the rete tubules.The receptacles, tubuli recti and rete testis are part of an organ which accomplished the connection of the gonad to its mesonephric excreto