occasionally found among frogs; the testis produces ova in places, and the Mullerian duct is retained and functional. The ciliated nephrostomata remain open to a late stage of development in the frog, and in many amphibia throughout life. Their connection with the renal tubuli is, however, lost.
Text Book of Biology, Part 1: Vertebrata · The Wunder Library — complete classics, free to read, with narration.