Up to 1876 the maternal mortality from the operation was about 52 per centum. Between 1787 and 1876 in the city of Paris there was not one successful caesarean section as far as the mothers were concerned. At present on an average less than 10 per centum of the women are lost, and expert surgeons have better results. Up to about 1902 Zweifel had made 76 such sections with only one death, and Reynolds, 23 with no death. Leopold has performed the operation four times on the same woman, and Ahlfeld and Birnbaum have reported instances where the same woman has had five caesarean sections performed upon her. The operation is, of course, capital, and always most serious, even in city hospitals. The indication for the operation is chiefly a narrow pelvis, which blocks the delivery of the child. There are no reliable statistics as to the frequency of narrow pelves in the United States; but Dr. Williams, of the Johns Hopkins University Hospital, in a series of 2133 cases found 6.9 per centum in white women and 18.82 in negroes. Normally the average female pelvis, at its narrowest diameter, is 11 centimetres wide. This part is called the conjugata vera, and it is the diameter from the promontory of the sacrum behind to a point on the inner surface of the symphysis pubis in front. In delivery much depends upon the size of the child, and in each case the obstetrician waits until he sees that delivery {56} is impossible by natural means before he resorts to the caesarean section or other operative interference. Of two women with pelves of the same contraction one may require the section and the other may have a normal labour. A bisischial diameter at the outlet of the parturient canal of 7 centimetres or less is an indication for section; so are certain tumours that block the delivery of the child. When the conjugata vera is less than 7 centimetres in flat pelves, or 7.5 centimetres in generally contracted pelves, the treatment varies in the customary medical practice according as the child is alive or dead, and it varies as the condition of the mother. The common medical doctrine will first be given here before the moral questions that may be involved are mentioned.