ABSTRACT
Sinus Termination o f the Ureteric Buds The mechanism whereby the ureteric buds terminate in the U-G sinus, separate and distinct from the meso nephric ducts, is still unclear.
• Mesonephric absorption: it is generally held that the epithelium of the trigonal area in the dorsum of the definitive bladder, extending from the ureteric openings down to those of the ejaculatory ducts (mesonephric ducts), is not derived from sinus endoderm, but mesonephric mesoderm. The com mon stalk uniting mesonephric duct and ureteric bud is indubitably absorbed in the initial period, explaining their permanent separation (Figure lc).
