OF THE PELVIS. 29 



of the sacrum, an obliquity which produces the sacro-vertebral angle, 

 or the promontory ; and by the presence of the ilio-lumbar ligament, 

 which extends from the last transverse vertebral apophysis to the 

 posterior extremity, and not to the posterior spine of the iliac crest, 

 as is incorrectly asserted by several modern authors. 



31. The obturator membrane, and the ligament of Fallopius, 

 which extends from the anterior superior spine of the ilium to the 

 spine of the pubis, constituting the crural arch, and separating, be- 

 fore it terminates, into two columns to form the inguinal ring, com- 

 pletes the ligamentous apparatus of the pelvis. 



SECTION 3. 

 Of the Pelvis in general. 

 §. I External Surface. 



32. The principal use of the external surface of the pelvis, which 

 is very uneven, is to give attachment to the muscles which surround 

 the coxo-femoral articulation; it may be divided into four regions. 



33. The first, anterior, bounded on the sides by the cotyloid cavi- 

 ties, presents, in its middle, the front of the symphysis of the pubis, 

 and laterally, the external obturator fossa, filled w^ith the correspond- 

 ing muscle. 



34. The seconA, posterior, bounded by the projection of the coxal 

 bones, is formed almost wholly by the posterior surfaces of the sa- 

 crum and coccyx. Consequently, we may observe in this region 

 the sacral crista and the lower orifice of the spinal canal; the sacral 

 portion of the vertebral grooves filled with the point of the sacro-spi- 

 nal muscle, and in the bottom of which are seen the ten posterior 

 sacral holes, from whence pass the nerves of the same name. 



35. The two last, lateral, enclosed by the preceding, present the 

 external iliac fossae above; below and behind, the posterior surface 

 of the sacro-ischialic ligaments, and the plane of the notches or holes 

 of the same name; below and forwards, the cotyloid cavity which 

 receives the head of the femur. 



§11. Internal ^Surface. 



30. The ancient authors have compared the pelvis to a barber^s 

 basin. Although trivial, this comparison, nevertheless, gives a pretty 

 exact idea of it. We may, with the moderns, divide its inner face 

 into two parts: one, superior, which bears the name of gre&ter ba- 

 sin, upper basin, or abdominal basin, on account of its dimensions, 

 its situation, or the parts it encloses; the other, inferior, and which 

 is also known as the lesser basin, or the pelvic excavation. 



