XVIII. Wheel of fortune symbolising man's rise and fall (l541

miniature).
MATTERS OF LIFE AND DEATH 209
Pregnancy tests
Experienced medical practitioners will assure you that women are much more interested in prognoses than men are. It is per- haps because women plan far less than men do, that they look upon the future as a closed book.
But women also consult their doctors for less general reasons, i.e. about specifically feminine problems. Thus many of them will turn to their doctor the moment they suspect that they may be pregnant. All pregnancy tests are diagnoses-cum-prognoses, for once a pregnancy has been diagnosed, we know precisely that — all being well — birth will result 280 days after conception.
Until thirty years ago doctors were generally unable to tell their women patients any more about whether they had con- ceived or not than the patients knew themselves: they would simply have to wait. Then, in 1927, two Berlin doctors Aschheim and Zondek perfected a method whereby pregnancy could be determined in its early stages. After a great deal of experimental work, they discovered that large amounts of oestrogen were present in the urine of pregnant women, and that if some of that urine is injected into a sexually immature mouse the ovaries of the mouse will show a marked reddening and the presence of corpora lutea. To make quite certain, the experiment has usually to be repeated with a number of mice, and that involves a delay which anxious women find quite un- bearable. In the Friedmann test, a speedier variation of the Aschheim-Zondek method, the urine is injected on two successive days into the vein running at the back of the ear of a virgin doe rabbit. Twenty-four hours after the second injection, the animal is killed and its ovaries are investigated. A newly ruptured follicle is a positive sign of pregnancy.
In more recent experiments with frogs, the time lapse has been shortened even further, and, in any case, the tests are kinder to the animals. Female frogs of the South American genus Xenopus, when injected with urine from pregnant women, will lay eggs after only eighteen hours. More surprising still is a technique discovered only a few years ago: the urine of male frogs which have had the urine of a pregnant woman injected into them, will be found to contain spermatozoa some 3-6 hours later. ^ ^ F. W. Roques et ah Diseases of JVomen (9th ed. London 19SS),p. 64.
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The prcx:esses involved are not yet fully understood, since the original hormone theories are no longer thought to explain the phenomena. The facts, however, are incontestable, and parti- cularly the older tests are thought to be exceptionally reliable: more than 90% of positive results are borne out by subsequent developments. Even so, the tests are not used as frequently as it was thought they would be: most children still see the light of day without a few small mice or a chaste rabbit having to lay down their lives for them.
Boy or Girl
While early determinations of pregnancy have a medical as well as a curiosity value, another branch of sexual prognosis has curiosity value alone: the prediction of the sex of unborn children.
Interest in this problem is age-old, and in earlier days, when the future existence of a noble line might have hinged on the answer, the problem was, in fact, of great importance. Small wonder then that there have been hundreds of theories about sex determination before birth — most of them sheer myths and old wives' tales. In the course of time these theories have under- gone great changes. Aristotle was the father of the fixed notion that a child's sex was determined by the seed, i.e. by the father alone. According to this doctrine (which was in vogue for almost a full 2000 years) young men sired mainly boys, older men produced girls, warm weather led to an increase in boys, and cold winds from the north to more girls. In other words, heat favoured the male sex. In the 17th century, all these theories were challenged by the ovum hypothesis^ according to which sex was determined by the mother, and, for the next two centuries, opinions were sharply divided. Graduallly it came to be accepted that both parents played a part in the transmission of physiolo- gical characters and in the determination of sex. However, at the turn of the last centuries, when the role of chromosomes in the transmission of genetic characters was first appreciated, McChung ( 1902) was able to show that, while father and mother
1 Morus: Eine fVeltgeschichte der Sexualitdt (2nd ed., Hamburg 1957), pp. 1 84 ff.
MATTERS OF LIFE AND DEATH 21 1
contributed an equal number of chromosomes to their joint offspring, sex was determined exclusively by the father's chromosomes.^
Other Aristotelian notions, too, adorned with new biological arguments, have come back into favour. Thus many biologists have taken up his idea of the influence of the climate not only on the number of births — the warmer the weather, the more children are conceived — but also on the distribution of the sexes. Where the climate is "stimulating", i.e. not too cold and not too warm, the number of new-born boys and girls is said to be approximately equal, while boys predominate both in very warm and also in very cold countries. ^
Such general observations are of little help to expectant parents, who, in the absence of unequivocal answers from the medical profession, have been turning to astrologers and other diviners for thousands of years. There is no pseudo-science that has not tried its hand at this game — ^none more so than pen- dulum-divination. As early as 3000 b.c, the Chinese were swinging pendulums to determine the sex of future heirs to the throne, apparently with little success, for the method was subsequently rejected. In the West, however, which is obviously far less daunted by failure, there is still an incredible number of people who believe that boys cause a pendulum to swing right across the stomach of a pregnant woman, while girls induce the pendulum to swing in a circle.
Europeans also attributed pre-natal influences to the moon. This seemed exceedingly plausible when the phases of the moon were seemingly related to the menstrual cycle. Although none of these lunar theories were ever proved to have any factual basis, many people continue to believe that boys will be conceived in the new moon, and girls when the moon is waning.
Still, even believers found this rule a little difficult to live by, for though the moon might govern their children's sex it did not govern their own passions. They therefore ignored the moon when it came to love-making, and resorted to other supersti- tions. In Italy, for instance, many pregnant women still cut off'a lizard's tail, and watch most carefully what happens. If the
1 L. R. Wharton: Gynecology (Philadelphia-London 1947), p. 38. * Andr6 Misserand: A la recherche du temps et du rhythme ( Paris 1940), pp. 146-159.
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lizard grows a new and flawless tail, a boy may be expected with complete certainty; girls are associated with stunted growths — ^not very flattering to the female sex, to be sure.
Cellular sex-differentiation
After centuries of futile attempts to solve this riddle by the most complicated methods — including the Cabbala — biology came to the rescue. The first promising step was taken in 1932, when the American doctors Dorn and Sugermann developed a method that is very similar to the Friedman pregnancy test: the urine of the pregnant woman is injected into the pinna of a male rabbit, though not before five months of pregnancy have passed. If the foetus is male, the rabbit shows no reaction, but with female foetuses there occurs a marked swelling of the rabbit's sexual gland. Unfortunately this simple procedure is not yet conclusive enough to have become very widespread.
Another method is based on the important biological dis- covery made by the Canadian anatomist, H. G. Barr. In 1949, while examining the brains of cats, Barr discovered the presence of a tiny brown spot in the nerve cells of female cats and its absence in tom-cats. Now, while the existence of such spots in the nerve cells of many animals had been known long before, no one had suspected that they were restricted to the female sex. Here was the first clear evidence that there were sexual dis- tinctions other than the well-known primary and secondary sex characteristics. Further investigations showed that Barr's dis- covery applied to human beings as well, and not only to their brain but also to their blood and skin.
It seemed reasonable to assume that these microscopic dis- tinctions must already exist in foetuses, and the only problem was how to relate this new knowledge to the practical prediction of an unborn child's sex. After vain attempts to arrive at clear results indirectly by analyses of the mother's blood and urine, three Israeli doctors decided to make direct investigations of the amniotic fluid withdrawn from the uterus of pregnant women. In Jerusalem, twenty women volunteered immediately, and so did forty women in New York. In either case, prognoses
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were fully confirmed by the sex the children turned out to be at birth.
Despite these successes, only a few doctors have agreed to apply a method that is not entirely without dangers. Still, it seems likely that future improvements will make it possible for every mother to know her child's sex well in advance, thus opening up a new field for medical prognosis.
Infection or Heredity^
While sex prognoses are largely based on curiosity, genetic prognoses would be of far-reaching individual and social importance. Unfortunately, the theory of heredity is still too young to be applied prognostically to all genetic phenomena. Genetics is barely 100 years old and many of its beginnings, viz. the theories of Mendel, Darwin, and of his cousin Galton — the founder of eugenics — were too general to be applied in individual cases. The only practical prognostic results which we owe to that early stage are largely based on the large-scale anthropological investigations of physical structure, profile, hair and eye colour, made particularly by Rudolf Virchow working with German school-children. However, it quickly emerged that such external characters were less valuable prog- nostic criteria than biochemical traits, too small to have been determined with the technical equipment of the time.
Things only changed at the turn of the century, and the year 1902 became a milestone in genetic history. For it was in that year that Mendel's hundred-year-old laws governing the appearance of hybrid peas were rediscovered by Prof. Bateson. Two years earlier, Karl Landsteiner, a Viennese pathologist, had managed to classify human blood groups and shown the physio- logical basis of blood relationships.
Some of the genetic consequences of these discoveries could be applied at once, while others emerged very much later. Thus, in 1940, a substance first discovered in the red blood cells of the Rhesus monkey, the so-called Rhesus factor, was shown to be present in 85% of humans who are said to be Rh-f-. Now, while the absence of the Rhesus factor has no ill effects in itself, a Rh-
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mother whose embryo has Rh+ blood from the father, is likely to unleash an intra-uterine blood struggle that frequently ends with the death of the foetus, or may cause the child's health to be severely impaired. All women ought therefore to have a blood test before marriage or at least at the beginning of pregnancy, since suitable treatment and preventive measures may greatly reduce the danger to the child's life. This is one of the most important prognostic achievements of eugenics so far.
In other respects, too, it has become clear that the mother's pre- and post-natal condition is of far greater importance than that of the father. Today it is generally held that there are much fewer directly hereditary diseases than was formerly believed and that, for instance, tubercular or syphilitic fathers do not transmit the infective organism with their spermatozoa. If the child is nevertheless bom with such infections, we can say with certainty that it became infected inside the mother's womb or during birth — which naturally does not mean that the mother herself may not have been infected by the child's father. Prog- noses of the child's health and protective measures to safeguard it — i.e. possible separation from the mother immediately after birth — are therefore mainly based on the mother's condition.
However, the father, even if he has not infected the mother, is not without any influence on his children's health. Thus non- infectious congenital defects, for instance diabetes, may be transmitted by parents of either sex. Arterio-sclerosis is claimed by some to be based on hereditary factors, and there has also been some talk about an hereditary predisposition towards cancer, but, by and large, the number of established hereditary illnesses has shrunk with the years. Even such classical examples as haemophilia and colour blindness have not really been proved to be hereditary by direct biological demonstrations. Better knowledge of chromosomes and genes — the specifically heredi- tary factors within the chromosomes — may well lead to more plausible explanations, but explanations and proofs are not the same thing.
The secret of family resemblance Though our knowledge of hereditary diseases is still full of
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gaps, it is nevertheless more advanced than our knowledge of the transmission of other hereditary characters. By these we do not so much mean the inheritance of genius or of special artistic talents, of which science knows little more than any layman can read from the family histories of famous men, but the trans- mission of physiological characters such as size, figure, eye and hair colour, etc., in short everything on which parent-child resemblance is commonly based. Now, all these questions are completely unsolved, for when we are told that genes producing blue eyes, i.e. eyes with little pigment, are not invariably trans- mitted, we cannot very well predict a child's eye colour from that of its parents. Nor do Mendelian principles with their dominant and recessive characters prove very helpful, for to apply them one would have to go many generations back — and which one of us can remember the colour of our great- grandfather's eyes?
Nonetheless, Americans in particular have compiled long lists from which parents may glean the probable appearance of their future children. Thus a popular scientific book^ tells us that if some members of the family of one of the parents have blue, grey, or green eyes, while brown is the predominant colour in the other parent's family, the children will probably but not necessarily, have brown eyes. Similarly with hair colour: if the family of one of the parents has predominantly dark and the family of the other predominantly fair hair, the children will probably have dark hair, but they may also have fair and more rarely red hair. If the family of one of the parents have prominent noses, the child is likely to have a prominent nose, if one of the parents is tall and the other small, the child will probably be small, and so on. Generally speaking, the more striking charac- teristics of the parents will be passed on to their children.
Now, if this general prognosis were true, one would expect mankind to become progressively more dark-eyed and dark- haired, more hook-nosed, and much shorter of stature. In actual fact, the Roman nose has become the exception rather than the rule, there is no marked dwindling in the number of fair people, and there is no doubt that Europeans have, in fact, grown much taller, probably because of better nutrition and better general
1 A. Scheinfeld: The New Tou and Heredity (Philadelphia-New York 1951), pp. 118-123.
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conditions. Thus students in Western Europe and North America are 2-^" taller than students two generations ago, and a mediaeval coat of armour would only just fit a modern adolescent. In 1956, when the Paris Museum of Costumes held an historical exhibition, special dummies had to be built to wear Rococo clothes which barely fitted modem twelve to fourteen year old girls. Only when it came to 20th century dress could living models be fitted into them.^
None of these developments can be explained genetically, and sceptics might well conclude that the achievements of genetics are extremely slight. In fact, they would be quite wrong, for genetics must be credited with considerable achieve- ments during the last fifty years. It is true, however that much work still remains to be done before genetic knowledge can be applied to prediction with any degree of certainty.
1 Report by Mme. Delpierre, Assistant Curator of the Musie Carna- valet and the Musee du Costume in Paris (December 1956).