20 Veterinary Obste fries 



areas, modifies greatly the form and relations of the various 

 segments. 



Arrests in the development of the genital tube may occur at 

 any point, which may interfere more or less with its form and 

 functions. The f u.sion in the utero-vaginial region may be partly 

 or wholly arrested, resulting in a more or less completely double 

 uterus or vagina or the Meullerian ducts may fail to develop as 

 such but remain as two dense solid cords, as is .seen in Fig. 51 

 where no uterus or vagina exists. 



A study of Fig. 51 shows that the uterine cornua and ovaries 

 were apparently well developed, the cornua contained consider- 

 able cavities which were distended with fluid, the ovaries showed 

 Graafian follicles and a corpeus luteum. The anterior, or oviduct 

 segments of the genital tubes are widely .separated from each other 

 and are not commonly the .seat of arrest of development. 



The Muellerian ducts in the male commence to disappear at 

 about the middle third of pregnancy, but small vestiges may re- 

 main in the adult male as the hydatids of Morgagni, which, in some 

 species of animals constitute small pedunculated bodies between 

 the testis and the head of the epididymis. They are supposed to 

 come from the anterior end of the ducts and are more prominent 

 in man than in our domesticated animals. At the posterior end of 

 these ducts, where they unite together, they are by some supposed 

 to form the so-called uterus ma.sculinus, a small sinus which ex- 

 ists in the superior wall of the urethra between the .seminal vesi- 

 cles, at the point of emergence of the vasa deferentia. 



The entire genital tract, having a common origin, has a gen- 

 eral type of construction, characterized chiefly by each having 

 three separate coats ; peritoneal, muscular and mucous. 



The peritoneal layer, which invests the genital tract almost 

 completely, is derived from that of the body wall, behind which 

 the ducts of Mueller originate. At the anterior extremity the 

 genital tract opens, through the pavillion of the oviduct, into 

 the peritoneal cavity, the continuity of the peritoneum being 

 interrupted at this point to be succeeded by the mucous mem- 

 brane of the oviducts. 



As the broad ligament consists of two peritoneal layers, re- 

 sulting from the departure of the genital tube from its seat of 

 origin behind the peritoneum, it follows that, along the line of its 

 attachment to the genital tube, the investment is interrupted to 



