THE EE PRODUCTIVE ORGANS. 593 



from tubes which originally belong to the excretory system ; the 

 oviducts being formed from the Miillerian ducts, and the vasa 

 deferentia of the male from the Wolffian ducts ; while other por- 

 tions of the embryonic excretory apparatus persist in a modified 

 or vestigial form, as accessory organs in relation with the repro- 

 ductive system. 



a. In the Male. 



The Miillerian ducts begin to atrophy about the middle of 

 the third month, and ultimately disappear completely along the 

 greater part of their length. The anterior end of the Miillerian 

 duct may persist, and in connection with it the hydatids of 

 Morgagni are believed to be formed ; this name being given to 

 one or more small pedunculated bodies, lying between the testis 

 and the head of the epididymis. One of these bodies is of larger 

 size, and more constant occurrence, than the others. 



It is stated that the posterior ends of the Miillerian ducts 

 unite together, and give rise to the uterus masculinus, a small 

 pocket-like diverticulum from the dorsal wall of the prostatic 

 portion of the urethra, a quarter to half an inch in depth, and 

 bearing on its margins the slit-like openings of the vasa 

 deferentia. The statement, however, needs confirmation. 



The Wolffian body and Wolffian duct. The greater part of 

 the Wolffian body disappears, but the anterior end becomes 

 intimately connected with the testis, and persists throughout 

 life. From the Wolffian tubules of this anterior end tubular 

 outgrowths arise, which during the fourth month grow into the 

 substance of the testis, and give rise to the vasa efferentia ; these 

 soon become connected with the seminal tubes, which latter, ac- 

 cording to Nagel, are formed directly from the germinal epithe- 

 lium. The anterior Wolffian tubules become the coni vasculosi ; 

 and the Wolffian duct is converted, in front, into the extremely 

 tortuous epididymis, and further back into the vas deferens. 



The structures known as the vasa aberrantia, a series of tor- 

 tuous tubular diverticula from the lower end of the epididymis ; 

 and the parepididymis, or organ of Giraldes, are probably per- 

 sistent portions of some of the hinder Wolffian tubules. 



b. In the Female. 



The Mtillerian ducts, at the beginning of the third month, 

 are still quite distinct from each other. Their anterior ends, 



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