386 DR D. BERRY HART. 



prepuce. Usually the ureteric openincr in the bladder is not 

 found on the same side, but in one of Benckiser's cases both 

 ureteric openings were found in the bladder. 



Practically the following explanations may be considered in 

 cases where there is an apparent vestibular ureteric opening. 



(1) The abnormal tube is due to the persistewe and patency of 

 the lower part of the Wolffian duct, and to the persistence of the 

 original communication between it and the ureter. 



(2) The abnormal tube is ureter entirely, with its lower end 

 displaced down. 



Explanation (1) involves the persistence of the lower part 

 of the AVolffian duct, and thus the question is raised as to the 

 course of the lower part of this duct. 



At the sixth to seventh week the Wolffian ducts open into 

 the urinogenital sinus below the eminence of Miiller — i.e., below 

 where the ducts of Miiller end blindly (fig. 12), and after 

 this the vagina develops more markedly. Nagel has stated 

 strongly that the lower ends of the Wolffian ducts atrophy 

 after this stage. His words are, " Mit dem Beginn dieser 

 selbstandigen Entwickelungsperiode der Scheide " (bei Embry- 

 onen von 2-5 cm. bis 3 cm. Eumpfliinge) "veroden die 

 Woltfschen Giinge und schwinden immer niehr " (S. 99 and 98). 

 Nagel is such an able and conscientious investigator that his 

 statement has seemed to many to render the explanation we 

 are considering untenable. I believe, however, that Nagel is 

 wrong in his statement, and for the following reasons: — 



I have been able to trace in the female fretus at the 3^ months, 

 the Wolffian duct ta the developing hymen, and have shown 

 that the lower ends of these ducts develop the hymen (fig. 21). 



Thus these apparently abnormally low ureteric openings are 

 really due to the persistence of the lower end of Gartner's canal and 

 of its original communication with the ureter. The following is a 

 brief recapitulation of the developmental stages concerned. 



The Wolffian duct iu the 3-2 mm. foetus opens into the 

 anterior part of the undivided primitive gut. From the Wolffian 

 duct the ureter buds off and grows up and back to develop the 

 ureter and kidney probably as fur as the extre mity of the straight 

 tubules (fig. 5). If the Wolffian duct remains patent and per- 

 sists in its lower part after developing the hymen at the third 



