30 OBSTETRICAL ANATOMY. 



more extensive as the vagina is narrow, and consequently as the female 

 is young ; it has been compared to the hymen of woman. Brugnone was 

 of opinion that it was attached to the upper surface of the vagina by a 

 small cord, and that it was the rupture of this by the forced entrance of 

 the penis which caused the slight flow of blood from the vulva observed 

 in Mares put to the horse for the first time. This is no doubt the hymen 

 to which he refers — a membrane found generally in the filly, though not 

 often in the Mare, but which, when present, separates the vulvular from 

 the vaginal cavity. This membrane forms a circular partition, fixed by its 

 circumference to the vulvo-vaginal walls along with the valve of the 

 meatus, and is perforated by one or more openings, which are sometimes 

 very small. Not infrequently old brood Mares show in this situation 

 pediculated appendices, which are the debris of this mucous diaphragm. 



The urethral orifice of the Mare is wider than that of the Horse, and 

 will readily admit a large catheter. In passing that instrument, it is well 

 to remember that the urethral canal curves forward and downward, and 

 that the valve must be raised either with the point of the instrument or 

 the finger before the passage can be entered. 



In ordinary circumstances the vulva is retracted, and with Mares which 

 have foaled several times, the^labia usually exhibit as many wrinkles or 

 folds as parturition has been frequent. 



During oestrum, but especially towards the termination of pregnancy, 

 the labia becomes tumified and soft, the inferior commissure descends, 

 the vulvular opening is enlarged, and from it is discharged a quantity of 

 tenacious stringy mucus. 



Differences in the Vulva of other Animals. 



Cow. 



In the Cow the lips of the vulva are larger, softer, and thicker, and the 

 inferior commissure, angular and prolonged into a curved peak, is fur- 

 nished with a tuft of hair. The meatus tiritiarius is disposed as in the 

 Mare \ but in the interior of the urethral canal, fixed to its lower aspect, 

 is a valve whose free margin is directed backwards ; this valve surmounts 

 a cul-de-sac about the third of an inch. This valve of the canal must be 

 remembered in passing the catheter into the bladder. About an inch 

 within the entrance of the vulva, and embedded within the substance of 

 its lips, are the vulvo-vaginal glands {glandida vagitice, S. I?uverneyi, S. 

 Barlltolini) — large almond-shaped bodies whose widest extremity is di- 

 rected upwards, and the narrow end, situated near the clitoro-ischiatic 

 muscle, is prolonged into their excretory canals. These are conglomerate 

 glands, whose excretory ducts unite to form a kind of sinus that at last 

 opens into the vulva, about the third of an inch from the labia. The cli- 

 toris is longer, and more tortuous and slender than in the Mare, and con- 

 tains a dense fibrous nucleus of a spiral shape. The vaginal bulb is much 

 more extensive than in the Mare, and is continued to the clitoris, where 

 it is covered by a thick muscle, which descends from the extremity of the 

 sacrum, and terminates on the clitoris. The same changes occur in the 

 vulva of the Cow as in the Mare during oestrum, and towards the termina- 

 tion of pregnancy ; the mucous secretion of the vagina is more abundant 

 in the Cow, however, and persists longer. 



