AUTENREITH'S ADDRESS. 7 



quity of the conjugate diameter, arising from the flexion of the loins forward, 

 render parturition more difficult, but the strength, likewise, of the dorsal 

 muscles, increased by exercise, seems to be equal to the drawing backwards 

 the pelvis of a young person of. tender years, and of forcing the promontory 

 inwards, and in this way to alter the form of the pelvis, and to render it 

 narrower." At all events, the conjugate diameter of that pelvis whose dorsal 

 portion was the largest, was shorter by six lines than the conjugate of that 

 pelvis in which the dorsal fossa (already described) was least. Perhaps it is 

 hurtful, therefore, to women to carry heavy weights on their backs ; or even, 

 perhaps, to affect too upright a style of walking, wherein the back and shoul- 

 ders are drawn backwards, and the os sacrum elevated by the great vigour of 

 the dorsal muscles. The chests of females, also, rendered stiff with whalebone, 

 perhaps injure them in a similar way ; nor is it only the narrowing of the 

 pelvis from side to side, or transversely, which ought to be attended to when 

 female clothing is considered, or the application of machines to the body 5 its 

 impression from before backwards ought also to be attended to. 



The dorsal portion of the crest of the ilium seems, for the most part, abso^ 

 lutely larger in men than in women, and the abdominal portion smaller ; but 

 the strength of the muscles is greater in man than in woman. 



I come now to the next remarkable difference between the pelvis of man 

 and other mammals, namely, the elongation of the symphysis of the pubis, 

 elongated into a semicanal, and to which Daubenton gave a proper name ; and 

 to the consideration of the fact of the inferior exit of the pelvis in quadrupeds 

 being directly opposed, or opposite, to the superior entrance or opening. In 

 the erect position, the human os sacrum is again bent forwards, which, from 

 its basis, on account of that very inclination of the superior aperture of the 

 pelvis, is curved backwards ; the coccygeal bones follow the forward curve 

 of the os sacrum, and complete it ; in this way the pendens-of the pelvis is 

 supported, the rectum and the vagina curved forwards, and a security is of- 

 fered against a prolapse, during any more violent effort. But the inferior 

 aperture of the pelvis would be too much narrowed by this curvature, were 

 the symphysis of the pubis not shortened, so that this shortest anterior wall 

 might be opposite to the longer curved wall ; together with this, the plane 

 of the superior aperture of the pelvis in man, is elevated much nearer to the 

 glance of the horizon than in the erect animal, Now the globular form of the 

 foetal head alone enables it to pass through this curved route, which leads 

 outwards around the symphysis of the pubis, as around an axis in the con- 

 cavity of the sacrum, from the superior or upper pelvis, through the inferior 

 exit ; and indeed so only that the short excavation of the mucha correspond 

 to the narrow symphisis of the os pubis ; and the long convexity of the 

 head, from the chin extending over the face to the vertex, correspond to the 

 long excavation of the pelvis, extending from the promontory to the apex 

 of the coccyx. The promontory which it must be admitted exists in infants, 

 and even in the foetus, though very obtuse and scarcely conspicuous, seems 

 attributable in point at least to the erect position of man, and to the contin- 

 uous efforts of the dorsal muscles. This promontory, narrowing or di- 

 minishing the conjugate diameter, and by its impression, as it would seem, 

 rendering the oblique diameter the larger, forces the head of the child to 



