KXTKHXAL on<IANs of (lEXEItAriON. 29 



The muscles of the vulva are constrictors — an anterior and posterior 

 — and are vohuitary. The anterior coustrictor is analoj^'ous to Wilson's 

 muscle in the male, and is formed of arciform fibres which surround 

 the sides and lower part of the vagina at its conmiencenient, its 

 extremities being continued by means of aponeurotic fascicuH as far as 

 the sides of the rectum, where they disappear. Posteriorly, this muscle 

 is confounded with the next to be described. The posleriur constrictor 

 {constrictor ciinm) is analogous to the constrictor of the vagina, and 

 forms a real sphincter; it is comprised within the substance of the lips 

 of the vulva. Superiorly, its fibres are" mixed with those of the anal 

 sphincter, and are attached to the sacrum by means of the suspensory 

 ligaments. Inferiorly, the most forward are fixed to the base of the 

 clitoris, and the middle are prolonged to both sides of the thighs, where 

 they are inserted into the skin. Inwardly, this muscle is in relation 

 with the vaginal bulb and the mucous membrane of the vulva. Its 

 external face is separated from the skin of the lips by a very vascular 

 cellulo-fibrous tissue, which is capable of contracting, and in the midst 

 of which are observed some isolated red nmscuhvr fasciculi — ^given off 

 from the principal nuiscle. 



The posterior constrictor of the vulva is very powerful, and in acting 

 during copulation contracts the vagina and compresses the penis ; by 

 reason of its attachment to the clitoris, when it acts it erects that organ. 

 In Mares which are rutting, the movements of the clitoris are frequent, 

 and it then projects outwards ; this is particularly observed after mic- 

 turition, and in this case the fibres of the constrictor attached to the 

 clitoris elevate the latter by acting on its base, those fibres which are 

 inserted into the skin of the thighs depressing the inferior commissure 

 of the vulva, which exposes that very sensitive erectile body lodged in 

 this space. 



The vuiscuhir liijaments of the vulva in reality correspond to the 

 li(jamcntuin suspcnsorium of the penis in the male ; they arise from the 

 lower face of the sacrum, and descend as flat bands until they untie 

 beneath the rectum, when they pass in several fasciculi into the lips of 

 this part, and mix with the fibres of the posterior constrictor. They 

 are composed of non-striated fibres. The skin, as already mentioned, 

 is very tine and thin, black in the great majority of Mares, has scarcely 

 any hair, and is very unctuous, odorous, and elastic. The bulk of the 

 vulva is made up of subcutaneous fascia, to which the skin closely 

 adheres ; as well as adipose and connective tissue, and bloodvessels and 

 nerves. 



The clitoris is an exact, but miniature, counterpart of the corpus 

 cavernosuni of the male penis. From two to three inches in length, 

 this body commences by two roots attached to the iscliial arch, and 

 which are covered by a rudimentary ischio-cavernous nmsclc. After 

 being fixed to the ischial sympliysis, by means of a suspensory ligament 

 similar to that of the male, it passes backward and [)rojects into the 

 vulvar cavity, towards the inferior commissure, in which it is lodged. 

 Its free extremity is enveloped in a mucous cap — the prcpntium, which 

 is plicated in dit}erent directions ; and towards the centre of the tubercle 

 is a follicular cavity containing sebaceous matter, and which represents 

 that in the extremity of the male penis. In every respect tlie clitoris 

 resembles that organ, having a fibrous framework, erectile tissue, 

 cavernous vessels or " plexus retiformis," and a pair of muscles — the 

 crcctorcs clitoridis. This organ is more especially the seat of venereal 



