34 OF THE PELVIS. 



77. The pelvis is the base of the trunk; it forms a complete ring, 

 the posterior half of which, says M. Desormeaux, supports the en- 

 tire weight of the body, while the anterior serves as its abutment, so 

 that the weight of the trunk and thoracic members, transmitted 

 through the vertebral column to the sacrum, expends itself first on 

 the ossa ilia, and next on the pubes, which press against each other 

 with more or less force. 



78. To the lateral parts of this circle are attached the pelvic 

 members, which in certain postures, in their turn, support the whole 

 of this burthen, whether conjointly or separately. This use of the 

 pelvis though interesting to the physiologist, is still more so to the 

 accoucheur, for it accounts for the vicious and singular forms that 

 are sometimes assumed by the pelvic cavity, when ossification either 

 proceeds too slowly or retrogrades. Another use of the pelvis is to 

 enclose and protect the bladder, the rectum, the uterus, the tubes, 

 and ovaries. During pregnancy it supports the womb, and main- 

 tains it in a proper attitude. During labor it gives passage to the 

 infant, by impressing upon it the most favorable direction, and by 

 affording a point d'appui to the soft parts of generation. 



SECTION 4. 

 Of the Deformed Pelvis. 



79. It would perhaps be more rational not to speak of deformities 

 of the pelvis, until we should come to treat of difficult labor; but the 

 custom of examining them immediately after treating of the natural 

 conformation having prevailed for so long a time, I have not felt my- 

 self at liberty to deviate from it. 



80. The pelvis is deformed whenever it is sufficiently altered, 

 either in its natural form or dimensions, to render parturition difficult, 

 dangerous, or impossible. In this view, a pelvis may be mal-formed, 

 although its conformation be regular, and it may have a mal-confor- 

 mation, although it be not deformed. Nevertheless, these two con- 

 ditions being almost always united, it has happened that the books 

 have commonly confounded them both together. Sacombe, it is true, 

 desired to see a distinction made between mal-configuration and 

 mal-conformation; but this distinction, being purely grammatical, has 

 not been adopted, and scarcely deserves to be combated. 



81. The direction of the axes and planes of the pelvis, the di- 

 mensions of its diameters, and even its form, are doubtless far from 

 being, in all pelves, exactly similar to those I have mentioned above; 

 but a few lines more or less, an inclination more or less decided, a 



