324 UNNATURAL EUTOCIA. 



the perforation of the membranes. The hips, arms, and shoulders 

 pass through the straits, and present themselves at the vulva in the 

 same way; that is to say, diagonally at the superior strait, and 

 antero-posteriorly at the inferior strait; but the act of rotation takes 

 place from left to right instead of from right to left, as before: both 

 the right hip and right shoulder, and not the corresponding parts of 

 the left side, proceed to lodge in the arch of the pubis; the abdomi- 

 nal surface turns towards the left, and thus takes the situation of the 

 posterior surface, which now looks towards the right iliac fossa; 

 the occipito-mental and bi-parietal diameters, and the occipito-breg- 

 matic diameter and circumference, preserve the same relations with 

 the axis, the oblique diameters and plane of the superior strait, and 

 with the coccy-pubal and bi-sciatic diameters of the inferior strait; 

 but the face and forehead are obliged to descend along the front of 

 the sacro iliac symphysis, and the pivot motion occurs along the 

 right anterior and left posterior inclined planes; in one word, the 

 second position differs no more from the first than the left hand does 

 from the right; and the mechanism of the one is so similar to that 

 of the other, that it would be really fastidious to enter into any longer 

 details concerning it. 



C. Third Variety. 

 Loins directly in front. 

 3d position, Baudelocque, MM. Gardien, Maygfrier, Capuron, Desormeaux, 

 &c.; 7 in 254, Madame Boivin; 6 in 235, Madame Lachapelle. 



782. It is true we find undoubted instances of the third position 

 in Mauriceau, Smellie and Levret, &c.; but as these authors, as well 

 as de La Motte, Deleury, and Asdrubali, did not distinguish them 

 from the two preceding ones, we cannot ascertain in what propor- 

 tion they met with them. Be this as it may, we do not perceive 

 that the form of the strait can in any way prevent such a presenta- 

 tion from taking place; the pelvis is wide enough in front to admit 

 of the two hips engaging in it transversely; the sacro-vertebral angle 

 might very well lodge betwixt the thighs or legs of the child, whether 

 flexed or extended, the belly and breast are too easily depressed to 

 occasion the least difficulty in this respect; and the shoulders them- 

 selves would pass transversely through the strait as easily as the hips. 

 As to the head, although in penetrating to the excavation it would 

 not experience more, or might have even less difficulty, than if the 

 vertex were presented in the third position, it notwithstanding rarely 

 fails to deviate to the right or left side of the promontory. It is easy 

 to see that in this respect there has been more dispute about words 



