422 A MANUAL OF ANATOMY, 



The second part of the rectum is enclosed by the in- 

 ternal sphincter, which is only an increase in the circular 

 muscular fibres, and has the levator ani supporting it at its 

 sides. Fig. 82. 



In front, is the lower part of the prostate, the base of 

 the triangular ligaments, the transverse peroneal muscles. 



THE PERINEUM, Female. 



THE LANDMARKS. 



Consult the male perineum for the boundaries of the 

 pelvic outlet, page 397. Notice the various differences 

 between the male and female pelvic outlet. The pubic 

 arch in the female is wider than in the male, and the 

 tuberosities of the ischium are farther apart. 



Comparative measurements of the male and female 

 pelvis (internal) : 



The female pelvis (Grandin and Jarman, " Obstetric 

 Surgery "). 



The male pelvis. 



Diameters. rim. Cavity. Outlet. 



Transverse, . . 4^ in. 4^ in. 3^ in. 



Oblique, .... 4^ in. 4^ in. 4 in. 



Conjugate, . . . . 4 in. 4^ in. 3^ in. 



The External Genitals. Fig. 85. 



These should be carefully identified. In comparing the 

 following descriptions with other text-books many smaller 



