148 



PELVIS. 



why elongation of these fibres should not take 

 place as well as of those of the investing liga- 

 ments. 



Tenon also asserts, that he has observed 

 relaxation of the pubic ligaments, even in the 

 male, during life. Sandifort considered that 

 in women who have borne many children the 

 pelvic ligaments become permanently looser. 

 In a female aged 79, dissected by Crnveilhier, 

 the symphysis pubis was exceedingly moveable, 

 the sub-pubic ligament had disappeared, and a 

 fibrous capsule invested the joint. Scemmer- 

 ring believes that separation of the pubes is 

 not rare, even during easy labours, and that 

 they remain permanently loose, and the pelvic 

 diameters larger, after many labours. Ac- 

 cording to the last author, the sacro-iliac 

 joints have also been found separated by a 

 cavity of the width of an inch in females who 

 have died during parturition. But it is a 

 question, whether this was not caused by 

 disease and deposit of pus. In a woman 

 mentioned by Frank, in Textors Neuem. 

 Chiron, (vol. i. p. 26 J.), the pelvis was so 

 moveable every time she became pregnant, 

 that she could not stand upright. Instances 

 of separation of the pubic joint during labour 

 are also mentioned by Eichelburg in East's 

 Magazine (vol. xvii. part iii. p. 550.), and by 

 Nicholson in Trans, of Physic, in Ireland 

 (vol. iv. 1821). Dr. William Hunter, in his 

 memoir upon this subject, gives two cases of 

 parturient women, in which the fibrous tissue 

 connecting the cartilages was replaced by a ca- 

 vity lined by a perfect synovial membrane, 

 and forming a perfect arthrodial joint; and 

 he concludes, that a certain relaxation of 

 the pelvic ligaments takes place in the latter 

 months of pregnancy and during labour, al- 

 lowing of a slight increase of the pelvic ca- 

 pacity, and a yielding to the shape of the 

 foetal skull. 



On examining the pelves of five women who 

 had died soon after delivery, Dr. Knox of 

 Edinburgh found, in all, a remarkable relaxa- 

 tion of all the ligaments of the pelvic joints ; 

 in one the bones could be made to slide over 

 each other. This anatomist also inclines to 

 the opinion that this process is a regular and 

 healthy one in the parturient female. This 

 opinion is also supported by the post-mortem 

 researches of the celebrated Rokitansky of 

 Vienna, who considers that, in parturient 

 women, the pelvic ligaments become soft, 

 relaxed, and stretched. 



In addition to the testimony on this side of 

 the question, M. Senoir read an essay on the 

 " Articulations of the Female Pelvis," at the 

 Academy of Medicine of Paris, on the 1st of 

 April, 1851 ; in which he concludes, 1st. 

 That the articulations of the pelvis proper 

 should not be considered as amphiarthroses, 

 but as arthroscs ; and, 2ndly. That analogy of 

 structure and composition leads him to think 

 that an effusion of synovial fluid from the 

 membrane lining the joints, causes the sepa- 

 ration of the bones sometimes observed. 

 (Bulletin de f Academic Nation, de Mcdccine, 

 t. xvi. No. 13. April 15th, 1851.) 



It is, however, considered by Baudelocque, 

 Boyer, Burns, Dewees, Denman, and I think 

 most English writers on Obstetrics of the 

 present day, that, in common cases, no sensible 

 relaxation of the pelvic ligaments takes place, 

 and that, when such relaxation does occur, it 

 should be rather considered in the light of a 

 morbid condition, as it adds very little to the 

 diameters, and is attended with severe in- 

 conveniences from rupture of the sacro-iliac 

 ligaments. 



Not withstanding, comparative anatomy, par- 

 ticularly in Cows, Seals and Guinea-pigs, to 

 be presently considered, presents us with a 

 strong analogical proof in favour of the doc- 

 trine of some parturient relaxation of the 

 pelvic ligaments in women. 



COMPARATIVE ANATOMY OF THE PELVIS. 

 In the different races of mankind, the 

 pelvis, as influencing in a very great degree 

 the form of the body, presents considerable 

 varieties. 



Camper, and afterwards Sosmmerring, re- 

 marked that Negroes had more slender loins 

 and hips than Europeans, consequent upon 

 narrower pelves. Scemmerring gives a com- 

 parative measurement of the diameters of 

 the brim in a Negro and an European of 

 adult size. In the Negro, he found 3 in. 

 Hi lines, long or transverse diameter ; in the 

 European, 4~in. 6 lines; in the Negro the 

 short or conjugate diameter was 3 in. 7 Hues, 

 and in the European, 3 in. 1 1 lines. From 

 Camper's measurements, the long diameter 

 was to the short one as 39 to 21\ in an adult 

 Negro, and as 41 to 27 in an adult European, 

 who, nevertheless, was of much less stature 

 than the Negro. 



The measurements in the table on page 151, 

 were taken in the dissecting rooms of King's 

 College, from an adult male Negro 6 feet 

 high. From the measurement of this pelvis, 

 the antero-posterior diameters seem to pre- 

 vail in the Negro, and the whole pelvis to 

 be smaller than in the European. This is 

 seen remarkably in the limited breadth of 

 the sacrum, (3 in. 9 lines), and in the ap- 

 proximation of the ischial spines (3 in.,) both 

 much lower than the average European ; the 

 latter, indeed, less than in the Chimpanzee. 

 In fact, I have never met with an European 

 sacrum so narrow as in the Negro above 

 mentioned, especially in an individual so tall 

 as 6 feet. 



This difference is remarkably contrasted 

 in the pelvis of O'Byrne, the Irish giant, 

 in the Hunterian Museum, in which the 

 iliac wings are remarkably large in compa- 

 rison with the true pelvis, and the sacrum 

 very broad. The superior pelvic outlet is 

 in this skeleton disproportionately larger 

 than the inferior, the ischiadic tuberosities 

 being nearly as close together as in ordinary- 

 sized pelves. This sudden narrowing of the 

 pelvis has evident reference to the better 

 sustaining of the viscera of the pelvis and ab- 

 domen. 



It is supposed that in Negro women ge- 

 nerally, from the easy labours they undergo, 



