whereas testicond reptiles contain an excurrent duct system, they lack male reproductive glands (absent seminal vesicles, prostate, bulbourethral glands). monotreme mammals are also testicond (like reptiles) and contain some, but not all (absent seminal vesicles) of the male reproductive glands observed in most metatherian and eutherian mammals. this combination of reptilian and mammalian structures within the monotreme reproductive tract has informed the evolution of the male reproductive tract in mammals. for example, the intra-abdominal low sperm storage capacity of the echidna (tachyglossus aculeatus) epididymis informed the role of the epididymis as the prime mover in the evolution of descended testes in mammals as it relates to lower extra-gonadal temperatures enhancing epididymal sperm storage in scrotal mammals. furthermore, the structure of the monotreme reproductive tract also informed prostate evolution in monotreme mammals.