130 



PELVIS. 



markable, as constituting the different pelvic 

 properties of certain classes of animals. 



It will also be observed that the transverse 

 diameter of the brim is the greatest in the 

 dry bones, but this is so diminished by 

 the presence of the iliac and psoas muscles 

 and fascia, that, in the living female subject, 

 the oblique is generally the best adapted to 

 receive the long diameter of the foetal skull. 

 The soft structures diminish the antero- 

 posterior diameters of the brim by about a 

 quarter of an inch, and the transverse, by half an 

 inch ; the diameters of the cavity being lessened 



about a quarter of an inch ; a fact which it is 

 necessary to bear in mind in estimating the 

 width in the living subject. The measure- 

 ments in the third double column were taken 

 from fourteen male and eighteen female sub- 

 jects in the dissecting room of King's 

 College, London, and are compared in the 

 first column with the contrasted measure- 

 ments of the male and female pelvis given by 

 Meckel, and quoted by most English writers 

 on the subject ; and in the second column 

 with those given by John James Watt, in his 

 work on the pelvis. 



a 4 inches (Burns, Ramsbotham, Lee, Cloquet, Velpeau, and Baudelocque). 

 Boivin). 4'3 inches (Rigby). 



b 4 inches (Burns, Lee, and Cloquet). 4^ inches (Monro and Murphy). 



c Increased to 5 inches or more by the mobility of the coccyx. 



d 10 inches (Burns). 9'G inches (Cloquet). 



c 10 inches (Cloquet). 11 inches (Burns). 



f 7 inches (Cloquet). 



s 4 to 4'j inches (Cloquet). 



4J inches (Monro and 



The circumferential measurement of the brim 

 in well-formed males gave in my own mea- 

 surements 2 inches to each of the ilia, 3 inches 

 to each of the pubes, and 4.J to the sacrum, 

 which, allowing -J- inch to each of the sacro- 

 iliac cartilages and \ inch to the pubic, gives 

 a total circumference of 15^ inches. In the 

 well-made female the ilia were found to be 

 each 2|, the pubes each 3^, and the sacrum 

 5 inches, giving, with the same allowance for 

 the sacro-iliac cartilages and -*- inch for 

 the pubic, a total of 17^ inches. Thus the 

 superior size of the brim in the female seems 

 to depend more upon the ilia than upon the 

 pubes, although the direct distance between 

 the ilio-pectineal eminence and the sacro-iliac 



joint differs little in the sexes, because of the 

 greater curve made by the female ilia. The 

 circumferential extent of the borders, at the 

 plane of the inferior outlet in a female pelvis 

 of average diameters, and dried with thesacro- 

 sciatic ligaments attached, was 14 inches. In 

 the fresh state it generally amounts to lo, as 

 the ligaments shrink by drying, and would be 

 extended to 16 inches, or more, by the ex- 

 tension of the coccyx and the elasticity of the 

 ligamentous portions.* 



* The circumferential measurement appears to be 

 one not generally estimated as much as its utility 

 in detecting variations of size depending upon shape 

 would seem to call for, in the female pelvis. A 

 reference to the subjoined table of variations of dia- 



