I940 



HUiMAN ANATOMY. 



the ejaculatory ducts, — the permanent representatives of the Wolffian ducts. In the 

 female the tract produces the entire urethra, since the orifice of the sexual canals 

 opens into the uro-genital sinus. The bladder, therefore, is composite in origin, its 



Fig. 1649. 



Broad ligament 



\ 



Bladder 



Symphysi.'^'. 



Clitoris 



Glatis 



Epithelial knob, 



Anus 

 Uro-genital sinus 



Spinal cord 



Xotochord 



Ureter 

 Miillerian ducts 



Wolffian duct 



Rectum 



Reconstruction of human embrj-o of nine weeks (25 mm. length) ; ureter has migrated to 

 bladder, leaving Wolffian and Miillerian ducts attached to urogenital sinus, which is com- 

 pletely separated from intestine. X 10. {Drawn from Keibel model.) 



upper part being from the allantois alone, while in the formation of the trigonal region 

 both allantois and cloaca take part. The remaining portions of the urethra in the 

 male are formed by the extension of the uro-genital sinus along the under surface of 

 the corpora cavernosa of the developing penis (page 2044"). 



