314 NATURAL EUTOCIA. 



763. Where the chin looks towards the left iliac fossa, the posi- 

 tion of the face answers to the second or fourth of the vertex. It is 

 rather more frequently met with than the preceding one, but does 

 not differ from it except that the chin slides on the left anterior in- 

 clined plane, and the bregma on the right posterior one, so as to 

 place the head in an antero-posterior direction, in order to pass the 

 perineal strait; and that the act of rotation must be somewhat easier, 

 if, as is asserted, it be true that the presence of the rectum may im- 

 pede that of the right occipito and fronto-acetabular positions of the 

 vertex. 



It IS said that the head has been, but very rarely, seen to emerge 

 from the vulva in a diagonal or even transverse position, but it does 

 not appear to me certain, that, in these cases, the observers were 

 not deceived by an incipient act of restitution. 



C. Mento-Sacral Position. 

 1st of Bandelocque. 



764. The third position is extremely rare, 1. Because the occipito- 

 pubic position, which must give rise to it, is itself not very common; 

 2. Because if it be true that it does sometimes or even pretty often 

 exist at the very beginning of labor, the contractions of the womb 

 soon transform it into a diagonal or transverse position, 3. Because, 

 if it should maintain itself for any length of time, the chin, which is 

 too prominent not to lodge against the sacro-vertebral angle, would 

 force the occiput to descend, or swing towards the centre of the 

 pelvis, and at last place itself in the third position of the vertex; 4. 

 Because it is evidently impossible for the chin, which must always 

 appear first at the vulva, to descend in this attitude as far as the an- 

 terior edge of the perineum, unless, as M. Desormeaux remarks, 

 the fo3tus be an abortion ; for the breast would then be entirely 

 within the pelvis at the same time with the head, and Stein would 

 have satisfactory reasons to maintain, with the ancients, that face 

 labors cannot, without danger, be abandoned wholly to the powers 

 of nature. 



In fine, all the face positions may be reduced to one fundamental 

 one, a species which comprises two, or three, or five varieties, right 

 and left mento-iliac, mento-pubic, and if it be preferred, two diagonal 

 ones, all of which have, for a last result, the arrival of the chin under 

 the arch of the pubis, in order that the head may pass the inferior 

 strait without obliging the breast and shoulders to descend antece- 

 dently thereto into the bottom of the excavation. 



765. Remarks. In practice we also meet with certain positions 



