| Abstract: | The number of nephron populations in the postinduction period was established in 6- and 8-days chicken embryos and the development of an individual nephron and its parts was studied. The investigation by microdissection method has shownand the number of nephrons is different along the length of the kidney. Only two layers ofthe nephrons were found in the cranial portion, while in the caudal direction their number increased up to 4-6 populations which distinguished from one another by the glomerule position, the length of the nephron and its segments. All the populations of the ventral nephrons enter immediately into the mesonephritic (Wolffian) duct, while the dorsal nephrons have a system ofcollecting tubes by which they are connected with the mesonephric duct. The development of mesonephros was accompained by the increase of the absolute length of the nephrons of all populationsand their segments.Laboratory of Individual Development, Institute of Physiology, Czechoslovakian Academy of Sciences, Prague, and Laboratory of the Evolution of the Kidney and Water-Salt Exchange, Sechenov Institue of Evolutionary Physiologyand Biochemistry, Leningrad. |
