[Development of the ductule system of the epididymis in the prenatal period of human ontogeny].

In 285 human embryos, prefetuses, fetuses and newborns by means of a complex of morphological methods, development of the epididymal canalicular system has been studied. The anlage of the epididymal canalicular system is stated to appear in embryos 13.0-17.0 mm long (the 6th week of development) and is presented as an accumulation of epithelial cells and primary germ cells between reducing glomeruli and mesonephric canaliculi. The canalization process of the cellular accumulations and their transformation into real canaliculi takes place during the first half of the prefetal period (the 8th week of development). Further growth and development of the epididymal canaliculi takes place in the craniocaudal direction and by the end of the prefetal period (the 12th week) the canaliculi of the head are already formed, they have a twisted course; within the limits of the body and tail they are yet poorly differentiated and their course is nearly straight. During the fetal period of ontogenesis, further differentiation of the epididymal parts occurs and structure of their canaliculi becomes more complex. They acquire a twisted course in all the parts of the organ; by the end of the fetal period the form and structure of the epididymal canaliculi resemble those of the definitive organ.