180 



PELVIS. 



was only 4 feet high, and had never walked 

 nor menstruated, the sacrum and innominate 

 bones were connected by cartilage only, but 

 the ischio-pubic rami were united. It pre- 

 sented, in size as well as form, the charac- 

 teristics of that of a child of six or seven 

 years old. The conjugate diameter was larger 

 than the transverse, the ilio-pectineal line 

 little curved, and the cavity funnel-shaped, 

 the sub-pubic angle being only 30^. The 

 bones were not rickety. The organs of 

 generation, both internal and external, were 

 infantile. The measurements and appearance 

 of this pelvis are contrasted by that author 

 with those of the dwarf previously described. 

 The arrest of development seems to have 

 taken place in the present case at a period long 

 before the changes of puberty, as shown by the 

 undeveloped genital organs ; so that the cases 

 differ only in the degree of immaturity. Such 

 cases as the latter are not likely to require 

 the aid of the accoucheur. 



In accouchements at a premature age, how- 

 ever, some of the yet-remaining peculiarities of 

 the infantile pelvis may present difficulties in 

 parturition, among which the contraction of the 

 diameters, if not their want of adult propor- 

 tions, will be the chief. At the period of 

 puberty, the transverse and oblique diameters 

 enlarge much more rapidly, in the female, than 

 the antero-postenor, and begin to preponderate 

 over them, while, at the same time, and in a 

 great measure in consequence, the pelvis begins 

 to assume its adult " standard " appearances. 

 The full development of size, however, is 

 somewhat later in being accomplished, and 

 depends upon the completion of the ossifi- 

 cation. These changes of the pelvis take 

 place, as explained -by Mr. Shaw *, somewhat 

 later than those of the upper parts of the 

 body, in the transition from the infant to the 

 adult state, but proceed to a greater extent, 

 so as to reverse the excess in proportionate 

 size from the upper to the lower extremities. 

 The pelvic growth and the developments of 

 puberty may, according to the same authority, 

 be retarded to a later period than the usual 

 age, fourteen years, by a weakly constitution 

 or rickets ; and the female, adult in age, still 

 remains infantile in pelvic development. In 

 a case mentioned by De Ereraery -f, the three 

 parts of the innominate bone were distinctly 

 separate in a female at so late -an age as 

 seventeen years. Some remarkable cases of 

 extreme mobility of the pelvic bones in chil- 

 dren are also related by Deventer. 



But the development in size may proceed 

 to its fullest extent, and yet the development 

 in shape and proportion be arrested, and the 

 transitional form unchanged. In a spe- 

 cimen given by Dr. Murphy, of a female 

 adult pelvis, the diameters were above the 

 standard size, but the antero-postenor dia- 

 meter was 5^ inches, and longer than the 

 transverse ; the transverse of the outlet pro- 

 portionately diminished ; the cavity shallow ; 

 and the general form of the pelvis infantile ; 



* Op. cit. 



t Dissertatio de Mutatione Figuras Pelvis. Leyden, 

 793, p. 14. 



but the bones perfectly ossified. The pelvis 

 has the shape and proportions of that of a 

 child, and the size of an adult female (see 

 fig. 1 13.). To judge from the appearance of this 

 specimen, as seen in the drawing given by Dr. 

 Murphy, it seems to be a pelvis in which the 

 transverse processes of the last lumbar vertebra 

 are enlarged, ankylosedto the sacrum, and ar- 

 ticulated with the ilia, giving the appearance of 

 five sacral holes instead of four. This would 

 account for the increased antero-posterior 

 diameter, and apparent elevation of the sacrum. 

 Cases of this kind are more especially de- 

 scribed in the latter part of this article. 



Dr. Knox has observed that the male pelvis 

 also sometimes permanently retains the infan- 

 tile form, to which it is normally more ap- 

 proximated than the female. In one of this 

 kind in his possession, the greatest transverse 

 diameter was nearest the sacrum, and only 

 fths of an inch larger than the conjugate. 



Fig. 113. 



Adult pelvis of infantile Jorm. (After Murpliy.) 



Masculine pelvis. In females of a robust 

 frame and powerful development of muscle, 

 and accustomed to hard masculine labour, the 

 pelvis often presents the character of the male 

 in many important respects. The transverse 

 measurement of the brim is proportionately 

 smaller, the antero-postenor diameter being 

 often increased, and the shape of the brim is 

 thus rendered more oblong; the sacrum is 

 narrower, the pUbic symphysis longer, and the 

 cavity deeper, and rendered funnel-shaped and 

 less roomy, by the approximation of the ischial 

 tuberosities ; by which also the sub-pubic 

 angle is diminished to 60 or 70. The ischial 

 spines are longer, stronger, and project more 

 inwards ; the ilia are less expanded, and the 

 bones larger, more massy, and more marked 

 than in the "standard" pelvis. 



Dr. Knox is of opinion that in many in- 

 stances the true pelvis may be of normal size, 

 and yet the haunches be remarkably narrow, 

 owing to a want of proportion of the true 

 and false pelvis ; so that while the walls of 

 the latter are flat, upright, and approximated, 

 the true pelvis is of proper dimensions. He 

 adds, moreover, that the opposite dispropor- 



