576 ANATOMY OF VEKTEBRATES. 



characters of sex and race. The male pelvis is shown in fig. 183, 

 62, 63, 64 : the female pelvis in ^g. 399. In the latter the sacrum 

 is relatively wider, and, anteriorly, it is less concave transversely 

 above, a, more concave vertically below, b. The ilia are broader 

 and shorter, with more capacious fossae : the ' obturator foramen ' is 

 triangular ; the ischial tuberosities are wider apart, and the sym- 

 physis pubis less deep. An- 

 ^^^ thropotomists call the part 



which is above the linea ilio- 

 pectinea, o, f, and promon- 

 tory of the sacrum, «, the 

 ' false pelvis ;' that beneath, 

 the ' true pelvis." Of this 

 the ' brim,' or * superior cir- 

 cumference ' e, f, h, incloses 

 the ' inlet ' ; the ' inferior 

 circumference,' boumled by 

 the ischial tuberosities, pu- 

 bic symphysis, and tip of 

 the coccyx, incloses the 

 * outlet' of the ' true pelvis.' The diameter from the sacral pro- 

 montory, «, to the pubic symphysis, h, is called the ' conjugate ' or 

 ' antero-posterior ' one ; that between the ilia taken at e, jT, or 

 half way between the sacro-iliac joint and the pectineal eminence, 

 is the ' transverse ' diameter ; the ' oblique ' diameter is between 

 the point of the brim nearest the pectineal eminence, c, and the 

 sacro-iliac joint of the opposite side, d. Of the pehdc outlet two 

 diameters are noted — the ' antero-posterior ' from the tip of the 

 coccyx to the lower part of the pubic symphysis, and the ' trans- 

 verse ' taken between posterior parts of the ischial tuberosities. 

 The following may be regarded as the normal extent of the 

 above diameters in the two sexes : — 



Auterior view of the female pelvis. 



In Man alone are the boundaries of the superior outlet on one 

 plane : the section through the ilium, in fig. 400, shows this to be 

 due to the direction of the body of the pubis, which is on the same 



