a. The Acetabulum, or socket of the hip joint.
c. The cut edge of the Womb.
c. The Foramen Ovale.
d. The top of the ilium bone, called the crest.
h. The Symphysis Pubes.
i. The ischium.
k. k. The pubic bones.
Plate XXXI.
Head in the right anterior occiput iliac position.
The mechanism of delivery is precisely the same, and all the movements occur in the same order and manner, as in the first position, but the reverse way. The rotation, for instance, being from right to left, instead of from left to right, and so of all the others.
The left posterior occipital position.—Delivery is effected the same in this as in the left anterior, or first position, excepting that the rotation is more extended, owing to the occiput being behind, as explained in the right posterior occipital position.
GENERAL REMARKS ON THE DIFFERENT POSITIONS OF THE HEAD.
In all the other positions, and their varieties, there is nothing that calls for special notice, or that is material in practice, the delivery being nearly the same in them all. No matter what position the head is placed in, the back of it nearly always comes to the front, under the pubes, even though it have to turn half round to do so. The cause of this is supposed to be the peculiar form of the parts, which give it a screw like motion, in its descent, and the shape of the external opening, which, being longest from before to behind, can only allow the long diameter of the head to pass through in the same direction.