FEMALE PERINEUM 369 



is now laid bare. In the anal triangle it agrees in every 

 particular with the same portion of fascia in the male. In the 

 anterior or urogenital triangle, however, owing to the difference 

 in the external organs of generation, there is a slight modifica- 

 tion. It presents the same two layers. In the superficial fatty 

 layer, where it covers the labia majora, there are dartos fibres 

 similar to those in the scrotum of the male. The deeper 

 layer has the same attachments as in the male, viz. to the 

 anterior lips of the pubic arch, and to the base of the uro- 

 genital diaphragm but it is not so membranous, and con- 

 sequently does not form so distinct a stratum. The two 

 fascial pouches are also present in the female, and are some- 

 times spoken of as the vulvo-scrotal sacs. Their separation 

 along the middle line is not due to the interposition of a 

 median septum, as in the male, but to the presence of the 

 urogenital fissure. 



ANAL TRIANGLE. 



Nothing need be added to what has already been written 

 regarding this portion of the perineal space in the male. In 

 both sexes the steps of the dissection and the parts found are 

 precisely the same (vide p. 345). 



UROGENITAL TRIANGLE. 



Superficial Perineal Vessels and Nerves. Under this 

 heading are included : 



. . . / The superficial perineal artery. 

 r> \ The transverse perineal artery. 



[ The posterior labial nerves. 



Nerves. *. The long perineal branch of the posterior cutaneous nerve of 

 ( the thigh. 



They have precisely the same disposition as the corre- 

 sponding vessels and nerves in the male, with this exception, 

 that they are somewhat smaller, and are distributed to the 

 labium majus, instead of to the scrotum. For a detailed 

 description of these structures, the student may refer to p. 350. 



Dissection. The superficial perineal vessels and nerves should now be 

 divided and thrown backwards, and the superficial perineal muscles cleaned. 

 These are three in number, viz. the transversus perinei superficialis, the 

 ischio-cavernosus, and the sphincter vaginae. The two first have a similar 

 position to the corresponding muscles in the male; the sphincter vagince 

 VOL. I 24 



