30 OF THE PELVIS. 



59. At birth the pelvis is extremely narrow and very much elon- 

 gated; the curves of the iliac crista are scarcely begun, and the 

 position of the ilium is almost vertical; the pelvic cavity is conoidal 

 and not excavated, the sacrum is so much elevated that a horizontal 

 line passes under the point of the coccyx at the same time that it 

 rests on the top of the pubis; its transverse are much shorter than 

 its antero-posterior diameters. The bones are still bordered with 

 thick layers of temporary cartilages, and the whole is so compres- 

 sible that the dimensions of the pelvic extremity of the fcetus may 

 easily accommodate themselves to those of the maternal pelvis dur- 

 ing labor. After two or three years, some new osseous points are 

 produced, but they do not always coalesce entirely with the rest of 

 the coxal bone until the age of fifteen or twenty years. The spine 

 of the pubis has even been seen to acquire a length of six or eight 

 lines, and remain movable like an independent piece, which has 

 caused it to be compared to the marsupial bones of the didelphic 

 animals. 



60. It is therefore not until the fifteenth or eighteenth year thai 

 the evolution and union of the several osseous points of the pelvis 

 are entirely completed; so that previously to this age it is not the 

 height of prudence to expose a woman to become pregnant. 



61. In men the pelvis always retains, in respect to its form, the 

 same characters it had in infancy. All its parts are narrower and 

 deeper than they are in women; the coccy-pubal diameter is only 

 three inches and a quarter, the bis-ischiatiy three inches, and the 

 bis-iliac four and a half. There are only seven or eight inches be- 

 tween the antero-superior spinous processes, and eight or nine from 

 the middle of one iliac crista to the opposite one. The arch of the 

 pubis is straight, not wide in front, and almost triangular; the sym- 

 physis of these bones is at least two inches long, and the thyroid 

 foramen approaches also to the form of a triangle; the sacrum is 

 much less curved, the excavation not so deep, and the superior strait 

 more inclined, rounder, more like an oval or a circle; the iliac fossae 

 are more hollow, the great trochanters are not so far apart, the bones 

 in general thicker, and especially more uneven on their outer sur- 

 faces; in the male pelvis, every thing bespeaks strength and solidity, 

 and is so arranged as to render progression easy. 



63. In women, on the contrary, the articulations are not so com- 

 pact, they are thinner; the iliac cristas are wider, and turned out- 

 wards more than the base of the thorax, which gives a greater breadth 

 to the hips. The trochanters widely separated, by increasing the 

 transverse extent of the base of support of the body, also render 

 walking more difficult, and give to the sex a gait that is altogether 



