The rest of the body then rotates in the same way, and the arms and shoulders pass through the external opening in the same direction as the hips. The left shoulder first moves to the right of the pubes, while the left passes behind; and then, just when they are both passing out, one comes immediately in front, and the other immediately behind, placing themselves in the long diameter of the Vulva.

The head passes through the superior strait in the left, anterior occipital position, and is often delivered in that way; but sometimes it rotates, and the forehead passes into the curve of the sacrum, while the occiput is placed behind the pubes. When this occurs the body also rotates, to accompany the head. This state of the parts is represented in the following Plate:—

PLATE XXXIII.

Anterior posterior position of the head, the occiput being in front, after the delivery of the body.

c. The Coccygis.
p. The pubic bone, in front.

At this period the head is passed the uterus, and there is therefore little or no contraction to expel it, so that it often remains a long time undelivered. It will be seen that the position is very unfavorable, the longest diameter of the head, the occipito frontal, being the presenting one, which makes it lie immoveably across. The means of assisting in such a case are plain enough, the forehead must be brought down while the body is raised, towards the mother's abdomen; this will throw the top of the head back, towards the sacrum, and change the presenting diameter. The forehead and bregma rapidly escape below, and the occiput passes out last. This is the way in which nature herself also completes the delivery in such cases, when she has the power.

DELIVERY BY THE BREECH IN THE RIGHT POSTERIOR SACRO ILIAC POSITION.

This position is the reverse of the preceding one, the Sacrum being behind, and to the right, while the Abdomen is to the left in front. The same movements are performed as in the first position, and the whole process is similar, only the reverse way. The Sacrum being behind however, has to rotate much further to come in front, precisely the same as with the head when in the posterior position.

The head generally follows the Sacrum, and the occiput comes under the pubes, as already explained; but sometimes only at the moment when being disengaged.