15G 



OSTEOLOGY. 



from the middle of the brim on one side, to the same point on the opposite- its 

 average measurement is five inches. The oblique extends from the margin of tto 

 pelvis corresponding to the ilio-pectineal eminence on one side, to the sacro-iliac 

 sympnysis on the opposite side ; its average measurement is also five inches. 



Fig. 100. Male Pelvis (Adult). 



101. Female Pelvis (Adult). 



The cavity of the true pelvis is bounded in front by the symphysis pubis ; 

 behind, by the concavity of the sacrum and coccyx, which curving forwards 

 above and below, contracts the inlet and outlet of the canal ; and laterally it is 

 bounded by a broad, smooth, quadrangular plate of bone, corresponding to the 

 inner surface of the body of the ischium. The cavity is shallow in front, meas- 

 uring at the symphysis an inch and a half in depth, three inches and a half in 



