Persistent Hymen 265 



also because of the danger of the transmission of disease to the 

 male and, through him, to other females. 



In purulent vaginitis, sterility is the rule, if not constant. 

 Perhaps the disease causing the vaginitis itself also involves 

 other organs and, independent of the vaginitis, induces sterility. 

 So it is with the granular or nodular venereal disease of cows 

 and other venereal infections. The handling of these has al- 

 readj' received consideration on pages 73 to 107. 



During the puerperal period, acute vaginitis may arise, caus- 

 ing sterility for the time, or, becoming chronic or leading to adhe- 

 sions of the vaginal walls, the sterility may become more or less 

 permanently fixed. The overcoming or avoiding of sterility as 

 a result of this affection is considered under ' ' Puerperal 

 Infections. ' ' 



10. Persistent Hymen. 



As already stated on page 32, the hj-men is a membranous 

 expan.sion, stretching across the genital canal between the vulva 

 and vagina, and represents the remnant of tissues existing be- 

 tween the proctodeal pit and the posterior extremity of the 

 embryonic gut. In domesticated animals, this membrane regu- 

 larly atrophies and disappears wholly, or nearly so, before birth. 

 Exceptionally, it remains until adult life. The persistence is 

 most common in the mare, so far as recorded in veterinary 

 literature. In a large proportion of cases, the remnants con- 

 sist of one or more narrow bands stretching across the genital 

 passage from above to below, not far from the median line. 

 The lower end is attached to the vulvo- vaginal boundary just 

 anterior to the meatus urinarius and, from that point, slopes 

 upward and more or less backward to the roof of the vagina. 



In other cases, the hymen persists to a much greater degree 

 and, in one instance, we ob.served a broad sheet stretching from 

 above to below and completely closing the left half of the 

 vagina. In this mare the hand could be passed along the right 

 side of the genital tract until it had reached the vagina and 

 then, by causing this organ to balloon, the hymen could be felt as 

 a broad membranous expan.se about 7 or 8 inches in its perpen- 

 dicular diameter and 5 or 6 inches horizontall)^ the entire 

 membrane tensely stretched. 



In another instance we ob.served a two-vear-old fillv with the 



