PRESENTATION OF THE PELVIS. 319 



head, he divided into regular and irregular or deviated ones. In the 

 former, the thighs are applied against the abdomen, the legs are bent 

 upon the thighs, and the breech and feet present together at the su- 

 perior strait, and the great oceipito-coccygeal axis is parallel to the 

 axis of the pelvic circle. In the latter, the fcetus is more or less 

 inclined to the right or left, forwards or backwards; the posterior 

 surface of the coccyx, or one of the tuberosities of the ischia, or the 

 forepart of the legs and the sexual organs, correspond to the centre 

 of the pelvis; most generally, the latter are reduced to the former 

 as soon as the waters are gone off; in other instances they maintain 

 themselves for a much longer time, retard the labor, and, in certain 

 cases entirely prevent it from terminating spontaneously. 



772. The regular positions may also become irregular, especially 

 after the rupture of the membranes, either because the feet continue 

 to descend pressed against the breech; or because one of the legs 

 rises up on the anterior surface of the trunk, while the other is 

 extended, and descends first; or because one of them becomes 

 situated transversely, so that the knee and heel press on two oppo- 

 site points of the strait; or because one knee descends together 

 with a foot or a buttock, or one of the legs is turned up in front, and 

 the other back; or lastly, because this last mentioned condition is 

 met with concurrently with one knee, one foot, or a foot and buttock 

 together, &c.; but in general, they remain frank until the conclusion 

 of the labor. The two legs and thighs then extend, and the feet 

 escape first. At other times, again, the legs rise upwards and the 

 child comes away doubled, or by the breech properly so called. In 

 other instances, the knees alone descend together, the feet continu- 

 ing to be applied to the ischia, which constitutes presentation of the 

 knees: whence it results, that there are really no primitive presen- 

 tations of the feet nor of the knees, and that until the rupture of the 

 membranes, there are no other positions except those of the breech. 

 Thus these various kinds of positions ought to be considered only 

 as shades of a single and even fundamental species, the presentation 

 of the pelvic extremity of thefcetus. 



773. Instead of six, Baudelocque proposes only four positions 

 for the breech, feet and knees; in the first the back looks forward 

 and to the left, forwards and to the right in the second, directly 

 forward in the third, and directly backwards in the fourth. MM. 

 Capuron and Maygrier have rejected the two latter, and substituted 

 for them two diagonal positions, which renders their classification 

 of the pelvic positions in all respects similar to the one they thought 

 proper to establish for the head. Madame Lachapelle has acted dif- 

 ferently; she retains Baudelocque's third and fourth; but in place 



