The word environment is here used to mean the total environment, physical and social, which for man means primarily the climatic and cultural conditions under which he lives and breeds. Fertility is used in the demographic sense of reproductive performance as contrasted with fecundity, or potential reproductive capacity.

Eleven unmarried women, pregnat for the first time and requesting a legal abortion through the referral service at the Marie Stopes Clinic in London, volunteered for the study. Each woman was given a focused open-ended interview by the investigator after her consultation session with the clinic doctor. The subjects were middle working-class, including one schoolgirl and four students. All but one were within the age range 18–23. Four women were Roman Catholic and the remainder were Church of England denomination. The minimum length of the period between first meeting the putative father and becoming pregnant was 4 months. Three women were living in situations that enabled the couple to spend the night together whenever they wished. One case of rape was included in the sample. Eight subjects had used some form of contraception at least twice. Only one woman used a female clinical method of contraception. Three of the four cases in which contraception was used on the occasion of conception involved the male using withdrawal. Two of the subjects continued the pregnancy and married.

Topics discussed in individual case histories and across all subjects were: attitudes to marriage, pregnancy and children before meeting the putative father; sources and extent of knowledge about conception and contraceptive; attitudes towards pregnancy and contraception; extent of contraceptive practice; reasons for not using contraception; relationship with the putative father in terms of the role of sexual intercourse, and discussion of marriage, the possibility of pregnancy and of preventing it; sexual behaviour of the couple; attitudes to sexual intercourse; role of responsibility for contraception; the woman's reactions to being pregnat and the reasons for whether or not she informed her parents about the pregnancy.

The observations from the study indicated that knowledge and motivation were individual factors that could not account exclusively for the circumstances contributing to the woman becoming pregnant. Factors in addition to those within the control of the couple were observed and these influences appeared to be the result of conventional socio-cultural conditions and conditioning. The absence of a sanctioning social atmosphere and the presence of stigmas discouraged effective contraceptive practice; these also appeared to be factors in the decision between abortion and continuing the pregnancy.

Since 1939 Sweden has had legislation regulating the legal termination of pregnancy, and up to now more than 100,000 such operations have been performed in accordance with this legislation. Official statistics and investigations by individual researchers have provided a large amount of material, which implies a pragmatic approach to the difficult and many-sided problem of abortion, and which makes empirical evaluations of different aspects possible.

Ever since the Registrar General began to give mortality rates for different marital condition groups, it has been observed that, in every age group and for both sexes, the widowed have higher mortality rates than the married. In his 1959 Annual Statistical Review, the Registrar General made some analysis of this differential in terms of causes of death. The excess mortality as compared with the married appeared to affect the diseases listed in Table 1. The Registrar General's commentary asked ‘Leaving aside the question of possibility of error (in statements of marital condition) is it possible that the effect of death of a spouse is such as to increase the likelihood of death in the surviving member of the partnership? Here the basis of discussion has little factual support but it seems right to suppose that in the period immediately following bereavement the general state of ‘shock’ indeed is such as to increase likelihood of death. In the majority of young and middle-age widowed persons, however, this period passes and adjustment takes place, often followed by remarriage. There will be some selection here similar in many respects to that affecting the decision whether single persons should marry. With the older person, however, adjustment is more difficult to attain, remarriage is less common and the surviving partner, particularly the man, may live under relatively unfavourable conditions.’

A study has been made of the effect of a vigorous family planning campaign on one particular aspect of family limitation, namely female sterilization. The increase in numbers seeking operation suggests that, over the country as a whole, the method is not being employed as often as it could be, though it is emphasized that operation, as well as other methods of contraception, are not likely to make impact on the population problem unless there is a defined national policy.

Professor Morton was Johnston Professor of Biochemistry in the University of Liverpool, 1994–66. He served on the Council of the Royal Society, 1959–61, and on the Council of the Royal Institute of Chemistry, 1955–61. He was the first Chairman of the British National Committee for Chemical Education and of the Food Additives and Contaminants Committee. He has also served on many committees dealing with vitamins, bread and flour, nutrition and biological research generally. In recent years he has been active on committees of the Natural Environment Research Council.

This lecture was given to a varied audience of staff and students at the University College of Aberystwyth on 25th February 1970. The Executive Editor is pleased to be able to publish this interesting and thought-provoking discourse on a problem of ever-growing importance.

In a sample of 165 FPA patients, 67% had stopped attending the clinic after 3 years. Half the loss could be accounted for by transfers, moves and ceasing to need contraception. The drop-out rate was not related to age, social class or number of children. Of the three methods generally pre scribed, the greatest attrition occurred amongst the cap patients. In a sample of twenty-seven LA patients, 48% had dropped out.

An epidemiological study has been made of rates of mental illness in a number of ethnic minorities who are immigrants to Britain, and have settled in a defined area of South London. Of the groups considered, those from Africa, the Old Commonwealth, India and Pakistan have the highest rates. The lowest rates were found in those from Cyprus and Malta, native Britons, and those from the Caribbean. After controlling for the effects of age, sex and social class it was found that the pattern of illness in a number of the immigrant groups differed from the pattern found in the native born. Those from Africa, the Caribbean and India and Pakistan manifested an excess of schizophrenia, while those from Eire manifested a dearth of such illness when compared with matched, native-born controls. The combination of the following factors was used to try to predict the rank order of illness rates among the ethnic groups considered: community integration; status isolation; status striving in a climate of limited opportunity; and selective migration.

Isolation of human populations, leading to genetic divergence, is well documented in island settlements and religious isolates. Demonstration or measurement of isolation is more difficult in mainstream populations. An attempt has been made to assess such isolation by simple methods of aggregate analysis from readily available data. The limitations of the data and methods of analysis are fully appreciated, but it seems that differences between areas are detectable. Hence the methods, simple as they are, warrant further application to other communities. The analyses, both of surnames and of marriage movement data, indicate limited gene flow in Northumberland in the 18th century. Such gene flow as did occur came mainly from neighbouring communities, and there was very little long-distance inflow. There was thus a high degree of population constancy and localization in Northumberland in the 18th century. This could well be a contributory factor promoting the known genetic variability of the area.

Owing to the rarity of triplets and higher multiple births, most studies of multiple births have been focused on twins. One of the fields of study which has attracted considerable interest is the association of biosocial factors with twinning. Although much work has been done in this field in Caucasian populations, very little investigation has been carried out in tropical areas, some of which have the highest twinning rates on record. In this paper, the results of recent studies on twinning conducted in Aberdeen (Scotland) and Ibadan (Nigeria) will be presented to illustrate the influence of some biosocial factors on twinning.

Sir David Owen, who should have given this lecture, died very suddenly and unexpectedly at the end of June.

U Thant said in a tribute: ‘David Owen was literally the first member of the United Nations Secretariat. He joined the United Nations directly from the San Francisco Conference in 1945…. As the first and only Executive Chairman of the Technical Assistance Board he was key organizer of what has now become the United Nations Development Programme…. When he left the United Nations a year ago to assume his new post as Secretary General of the International Planned Parenthood Federation he was continuing the work to which he had devoted his life, the application of human ingenuity and technological progress to problems of peoples of the world. It is a tragedy, and a loss to all mankind, that his life and his new career have been so abruptly cut short.’

A study was made of the return of spontaneous menstruation and fertility in 121 Thai women who had received contraceptive injections of medroxyprogesterone acetate (DMPA) at intervals of 3 or 6 months with supplements of oral oestrogen at monthly intervals and who, for various reasons, had discontinued medication after 6 months or more.

Spontanecous menstruation returned in 113 of the women within 6 months, but no direct relation was found between the number of injections, period of usage or total dose of DMPA and the time required for the return of menstruation.

Of the 121 women who discontinued medication, only seventeen stated that they did so because they wished to conceive. Of these, twelve became pregnant within 10 months and three more within 27 months. The 104 women who discontinued medication for other reasons had a much lower pregnancy rate and must be supposed to have used, at least to some extent, other methods of contraception.

In December last year I received a letter from Dr Egon Szabady, Director of the Demographic Research Institute in Budapest, Hungary, calling my attention to the publication by the Institute of the abstracts of papers given at the 9th Hungarian Congress of Biology held in May 1970. Dr Szabady also enclosed a copy of the script of his opening address at the Congress, Population Science and Human Biology, in which he referred to letters which passed between Francis Galton and Jozsef Kórösi between 1894 and 1897, and a reprint of his paper, published in Demographia 1970, which gives a full account, with some facsimiles, of this correspondence. On inquiry, I found that this contact between these two great men of science had attracted little attention—Pearson's massive biography of Galton contains only two references to Kórösi, one to isogens constructed by Galton from Kórösi's Budapest data and the other to Kórösi's death. I wrote, therefore, to Dr Szabady asking permission to use his material in a note in JBS. In reply, Dr Szabady not only gave me his permission and that of the library of the Hungarian Central Statistical Office which holds the originals, but also sent me photographs of two postcards and two short letters not included, either in print or facsimile, in his Demographia paper. Additionaly, he sent me photographs of the two letters from Kórösi to Galton, published in print in Demographia, explaining that the copies held by the library of the Central Statistical Office were Blurred Because of being made by Kórösi on very thin paper. However, they showed, what I had not previously realized, that Kórösi's letters were written in English. I am most grateful to Dr Szabady for this courtesy.

In all societies for which data exist, there is seasonality in the incidence of births, a major cause of which in the UK appears to be season ality in sexual activity.

In contrast to the findings of Cowgill for earlier periods in other places, there has recently been in Great Britain a greater degree of seasonality in legitimate than in illegitimate births and in upper-class than in lower-class births.

Part of the explanation of the change in illegitimate seasonality could be the recent increase in the numbers of illegitimate births. The greater seasonality of upper-class births could be due to longer and more mobile holidays.

Editorial note. March 17th, 1971 was the fiftieth anniversary of the opening by Marie Stopes of her birth control clinic in Holloway, London, the first of its kind in the UK and possibly in the world. In recognition of this notable event, the Board of the Marie Stopes Memorial Foundation, in conjunction with the University of York, has established a Marie Stopes Memorial Lecture to be given annually for a term of years. The first of the series was delivered on 12th March in the Department of Sociology, University of York, by Mr Laurie Taylor of that department. In introducing the speaker, Dr G. C. L. Bertram, the Chairman, emphasized the great contribution made by Marie Stopes to human welfare and gave a brief history of the clinic, which was soon moved to Whitfield Street. On Marie Stopes' death in 1958 the Memorial Foundation was set up to manage the clinic, still in Whitfield Street, and as a working monument to a great women.

Mr Taylor's script is printed below as delivered and it will be seen that the lecture was a notable one. Not only that, but it was delivered with the verve of a Shakespearean actor and the members of the large and appreciative audience will not readily forget the occasion.

The reproductive behaviour of human beings, in contrast to that of other animals, is distinguished by almost universal awareness of the connection between sexual activity on the one hand and the birth of children on the other. There are, it is true, some classic examples where this connection apparently is not appreciated, as for example, the Trobrianders as described by Malinowski (1937), and the Arunta of the Central Australian desert as described by Spencer & Gillen (1927). These, however, are exceptions rather than the rule. In any case, even in them, reproductive behaviour is still constrained by custom although the connection is not appreciated. The biological potential to reproduction therefore does not, in itself, determine the level of fertility in any human population. Some individuals, or some categories of persons, may deliberately attempt to influence the natural process of reproduction, either to enhance or to inhibit its efficacy.

Human pregnancy wastage is probably of the order of 50%. It is greatest in the earliest weeks of conception when there is a close correlation with defective embryogenesis, approximating to 100% in the first 3 weeks.

Approximately 36% of all clinically recognized abortuses have a chromosome anomaly. This figure does not represent the primary incidence of heteroploidy at conception, because it excludes pre-implantation and early implanted losses which are not recognized clinically.

This heteroploidy is most common in early pregnancy at the time when pregnancy wastage is highest. It is not a homogeneous problem but involves a wider range of chromosome anomalies than those found in the adult, autosomal trisomies, XO monosomy and triploidy being the most common findings.

It follows that errors in gametogenesis, fertilization and early cleavage divisions are a major cause of prenatal mortality. Biological factors which predispose to these faults include maternal ageing, pre-ovulatory and post-ovulatory ageing of the oocyte and ageing of the spermatozoon. Parental chromosome rearrangements are of minor importance as a cause of chromosome anomalies in abortuses, although they may be of greater significance in recurrent abortions.

The rural parish of Turcifal in Portuguese Estremadura in 1671 reflected its standard of living in an unexpected fashion. If the prices of grain grown by the people of this parish are used as an economic guide with high prices reflecting poor agricultural years and low ones representing successful harvests, and such data are then compared with the local statistics, interesting demographic facts result. The mean annual number of marriages and births did not differ significantly between good and bad harvest years. There were, however, a statistically significantly larger number of girls born in poor harvest years; whereas in good years boys were born in excess of the expected sex-ratio. It is suggested that poor nutrition during pregnancy, or possibly some other factor influencing both simultaneously, increased the incidence of unsuccessful gestations, which are more likely to be of males, resulting in a proportionately higher number of female live births.

Linear correlations between the price of wheat or barley and the mortality of females showed high significance when the grain is barley and a low significance when it is wheat, suggesting that there may have been a differential use of the food supply. No significance appears when the price of grain is compared with male mortality implying that the men had preferential access to scarce food. The sex-ratio at death, including all ages and all causes, shows an excess of females.