The natural history of population : University of London Heath Clark Lectures 1937 delivered at the London School of Hygiene and Tropical Medicine / by Raymond Pearl.

  • Pearl, Raymond, 1879-1940.
Date:
1939
Catalogue details

Licence: In copyright

Credit: The natural history of population : University of London Heath Clark Lectures 1937 delivered at the London School of Hygiene and Tropical Medicine / by Raymond Pearl. Source: Wellcome Collection.

    314/436 (page 298)
    14th, 1928, or roughly 4! months from the last monthly period, it was clear that the pregnancy was progressing, so I again dilated to 24 Hegar and delivered a normal conception from below, having some little diffi¬ culty with the head of the foetus. The foetus appeared to be about months old, so that the pregnancy at the time of the first curettage must have been about six weeks old. In the first case the pregnancy was probably about the same age. [Case 3.] ‘It is generally believed . . . that extensive operations on the cervix are apt not merely to terminate a pregnancy but to predispose to abortion. This is not always the case. ‘A Korean woman, aet. 32 . . . was admitted to the Peking Union Medical College Hospital on December 17th, 1924 for profuse, in¬ tractable leucorrhoea of ten months duration. She spoke Chinese very poorly and had had four full term deliveries. The last monthly period had been on or about November 21st, 1924. She had a hypertrophied nodular cervix with much endocervicitis. On December 27th, 1924 a Sturmdorf operation was done by Dr. N. J. Eastman, the cervix dilated to No. 19 Hegar, a Hegar dilator No. 5 being passed into the uterus at the close of the operation, and a uterine probe passed during the post operative examination on January 12th, 1925. On August 28th, 1925 she came to hospital in labour with a full term pregnancy. The cervix dilated badly and as the lower uterine segment was thinning out, the husband was sent for in order to get permission for a Caesarean section. Less than an hour later she suddenly ruptured her uterus. Coeliotomy was done, followed by a supravaginal hysterectomy and she made a good recovery. So that in this case passing a No. 5 Hegar and a uterine probe into the uterus, combined with the Sturmdorf operation, failed to arrest a pregnancy which must have been about three weeks old at the time of operation.’ 22 This discussion is, to a considerable extent, based upon two recent studies (Pearl, 36, 37). 23 The practical breeder, as well as the laboratory worker, is familiar with this fact. Sterility occurs commonly in forms where the usual lushness of multiplication does not suggest the occurrence of sterility. Thus, to take only two examples byway of illustration, Sure and Beach (30), in a particular series of experiments with rats, found 9 sterile out of 88 females, or 10 per cent., under the conditions of experimentation. In some experiments of the writer with the fruit fly Drosophila melano- gaster there were, among 2,045 pairs of flies used as breeders in 100 consecutive generations, 496 completely sterile pairs, or 24-3 per cent. Yet even so there were produced in the hundred generations 217,221 offspring flies. Similar data for a genetically different group, in which there were 2,221 breeding pairs in total, show 263 sterile pairs, or n*8 per cent, and a total production in 100 consecutive generations of 191,296 offspring flies. Under the conditions of experimentation the first group, because of its high innate fertility, and in spite of its also high