only after the escape of the liquor amnii and towards the end of the second stage, when the posterior fontanelle is in the mesial line, and then the heart may be heard in the linea alba.

In the third position,' that is, the head lying in the right oblique diameter (occipito-posterior), and the back directed towards the mother's loins, the foetal heart will be heard loudest on the same level with the second position, but posteriorly.

2

And again, in the fourth position, the head lying in the left oblique diameter (occipito-posterior), the pulsations are heard on the same level as in the first, but more posteriorly.

Rotations from the third to the second, and from the fourth into the first positions, may thus be followed.

3

In breech presentations, of which there are four, the heart is heard most distinctly in the dorso-anterior pelvic presentations (two). Thus, in the first position, where the transverse diameter of the breech occupies the left oblique diameter of the pelvis, its sacrum towards the left acetabulum, the left trochanter towards the right acetabulum, and the right trochanter turned to the left sacro-iliac synchondrosis, the sounds of the foetal heart will be heard almost in the median line, at the umbilicus; in the second position, to the right and rather posteriorly.

In transverse presentations, the pulsations may be heard, stated generally, in a line running across the abdomen.

In face presentations, the front of the chest is most contiguous to the uterine parietes. Consequently, in mento-pubic positions, the heart is heard anteriorly in the iliac region; and rather posteriorly, when the face lies in the mento-sacral position.

The diagnosis of twins is much facilitated by auscultation." Suppose one fœtus lying in the left side, with the head presenting, and the other in the right, the breech presenting, the pulsation of the former will be heard midway between the anterior superior spine of the ilium and the umbilicus, those of the latter high up and to the right of the umbilicus. The pulsations will not, as a rule, be synchronous, and will be heard loudest at two distinct points in the abdomen, separated by very weak sounds. diagnosis is of course much easier after the escape of the liquor

amnii.

The

I may mention here a case in point: When examining a patient in the Edinburgh Maternity Hospital (some years ago), about three weeks before her confinement, the foetal heart was heard beating distinctly at 120 per minute in the right groin, and again at the same time another heart, at 154, high up in the left hypochondrium. The presence of twins was diagnosed, which proved to be correct.

'See Plate I. Fig. 3.

2 See Plate I. Fig. 4.

3 See Plate II. Fig. 1, from Leishman.

4 See Plate II. Fig. 2.

5 See Plate II. Fig. 3, from Tanner.