PECULIAR TO MAX. 12? 



spine, and its length exceeds its breadth ; so that tlie rela- 

 tions of these two dimensions are very different in man and 

 this animal*. In the latter, the symphysis pubis is very 

 deep ; and in both, there is neither that incurvation of the 

 sacrum, from the promontory downwards, nor that direction 

 of the coccyx forwards, which with the broad horizontal 

 expansion of the ilia, and the shallowness of the symphysis 

 pubis, are peculiar to the human frame, and make it a broad 

 and firm basis for the trunk, on wliich the weight of the 

 abdominal contents, and particularly of the pregnant uterus, 

 is supported. The lower part of the sacrum and the os 

 coccygis are turned forwards In man, and form the only firm 

 bony resistance, in the inferior aperture of the pelvis, to the 

 abdominal viscera, forced downwards by the diaphragm and 

 abdominal muscles. These bones are straight in all other 

 animals, because the weight of the viscera is differently 

 supported. Even in the orang-utang, the sacrum is flat and 

 contracted, and continued, together with the os coccygis, in 

 a straight line with the vertebral column. If the human 

 sacrum and coccyx had been continued in a straight line with 

 the spine, as tliose of the orang-utang and monkeys are, the 

 ossa innominata remaining as at present, they would have 

 projected beyond those bones, so as to disable us from sitting. 

 The curve which they describe, in man only, obviates this 

 inconvenience ; and allows the pelvis to rest securely, in the 

 sitting attitude, on the broad and strong ischlatic tuberosities. 



The influence of this structure on the direction and func- 

 tions of the vagina will be considered afterwards. 



The distribution, size, and ofhces of the muscular masses 

 correspond to the organic arrangements of the skeleton. 

 The lateral and posterior surfaces of the pelvis give origin to 

 the powerful glutei, of which the exterior (glutei magni), 

 exceeding in size all other muscles in the body, and covered 



* The height of the whole pelvis, from the tuber ischii to (he crista of the 

 ilium, is: 7 in. 3 li. in man. 



6 in. in the orang-utang. 



its breadth, between the flO in. 6 li. in man. 



two anterior spines, L 6 in. G li. in the orang-utang. 



