THE METANEPHROS. 689 



According as the embryo is a male or a female, so one or other 

 of these ducts develops. In the male the Wolffian duct remains 

 as the vas deferens, and the Miillerian duct becomes atrophied. 

 In the female, on the other hand, the Miillerian duct forms the 

 organs for the conveyance of the ova out of the body, and the 



FIG. 279. 



Diagram of the genital organs of an embryo previous to sexual distinction. (Allen 

 Thomson.) W. Wolffian body. 3. Ureter. 4. Bladder. 5. Urachus. gc. Genital cord . 

 cp. Clitoris, or penis, m. Mttllerian duct. w. Wolffian duct. . Intestine, ug. Uro- 

 genital sinus, cl. Cloaca. Is. Part from which the scrotum or the labia majora are 

 developed, ot. Origin of the ovary or testicle respectively. *. Part of Wolffian body 

 subsequently developed into the coni vasculosi. 



Wolffian duct is represented by a rudimentary structure near the 

 ovary. 



Part, however, of the Wolffian duct in both sexes develops 

 similarly ; this, the metanephros, corresponds to that part of the 

 duct nearest to the tail end of the embryo. It forms part of the 

 urinary organs, and develops into the permanent ureter and the 

 kidney. 

 68 



