HISTORICAL BACKGROUND OF REPRODUCTION: THE EGG-SPERM DEBATE
In the spirit of Aristotle, the physician Galen (129-circa 200 A.D.) claimed that the male seed is produced in the right testis (ovary) and then implanted in the right side of the uterus where it assumes active male characteristics. In contrast, the female seed is produced in the left testis (ovary) and then implanted in the left side of the uterus where it assumes passive female characteristics. Because Galen believed that the left side of the uterus was fed by impure, unheated blood, he concluded that women were deficient in heat. Since women are relatively cold, they cannot generate enough warmth to develop their bodily organs, including their sexual organs. As a result, cold-blooded women are able to produce only imperfect seed, which has less impact on reproduction than the perfect seed of warm-blooded men.
Although arguments about the respective merits of the female and male reproductive cells continued into modern times, by then scientists were using empirical data rather than speculation to support their theoretical claims. After many painstaking observations, the English physician William Harvey (1578-1657 A.D.) announced that "all animals reproduce by eggs. Harvey rejected earlier proposals that the "male semen becomes part of the fetal body and even that it finds access to the uterus. He considered the egg far more important than the sperm in the production of new animal organisms, regarding the sperm as a catalyst that simply triggers the egg to begin development. Working with a primitive microscope and a lively imagination, the Italian anatomist Marcello Malpighi (1628-1694 A.D.) later claimed that Harvey was correct to emphasize the role of the egg in animal procreation. The animal egg, said Malpighi, contains a minuscule form of the adult animal waiting to be triggered into production.
A swing back in the direction of emphasizing the role of the sperm in animal procreation took place when the Dutch histologist Anton van Leeuwenhoek (1632-1723 A.D.) used his microscope to study semen samples. To his amazement, he discovered a great quantity of living "spermatic animalcules" in the semen. Subsequent analysis led the embryologist Hartsoeker to insist that tiny preformed beings, or homunculi, could be seen if a spermatozoon were viewed without its covering. This was a complete turn around from the proposals that the egg contained the preformed being. Now the egg was seen as little more than the nourishment for the male seed.
The egg-sperm debate did not end with these discoveries. The controversy raged on. Those that advocated the theory that the egg was the crucial element in procreation and those that supported the homunculus, or little-man-in-the-sperm, theory each proposed more and more imaginative explanations to support their claims. Given the spirited manner in which these claims and counterclaims were made, it is easy to forget that the sperm was not discovered until 1677 by van Leeuwenhoek and that the mammalian egg was not properly identified until 1827 by Karl Ernst von Baer.
Unfortunately, the egg-sperm controversy, fueled more by ignorance than by knowledge, has continued until the present time. Its flames have been fanned by folklore and fable, mystery and superstition. As we do not wish to add to this nonsense, we intend to discuss the respective roles of the egg and the sperm in more dispassionate terms. There is no need to valorize either the egg's or the sperm's reproductive role because, as things stand (though this could change), both are necessary for procreation and neither alone is sufficient. The process of reproduction is complicated enough without permitting cultural lenses to distort biological facts.
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Womens Health
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PUBERTY
All of a sudden, strange things start to happen to our young Miss as she begins to grow up.
It can commence anywhere from nine years of age onwards. In recent years, for reasons unknown, it seems to be commencing at a younger and younger age in western lands. No doubt it is tied up with today's sophisticated way of living, earlier psychological development and earlier mental stimulation, all of which play a potent part. It is referred to as puberty.
Suddenly the system starts to develop potent chemicals, called sex hormones, and these have a rapid and far-reaching effect on many parts of the system.
Suddenly breast development commences. The unnoticed, flat, pinkish nipples become more marked, rounded and protrude as they rapidly increase in size. This is most noticeable between the ages of 8 and 15. Pubic hair commences to grow, this becoming obvious in the 8-14 age group at any time. Underarm hair also makes an appearance.
Menstrual periods make a tentative start, and anywhere from 10 to 161?2 years they will become more and more regular. There is usually a dramatic increase in height; this is called a 'height spurt' and takes place in the 9-141?2 age bracket.
The skinny, school-age child is transformed within a few short years into a modern young woman of vastly different appearance and shape. Most tend to put on weight, but there is an alteration of the system's fat deposits, giving the body the characteristic female curves which tend to remain for life. In brief, Nature has transformed her into an adult, with the physical and psychological issues that this involves.
But although the ages quoted are 'averages', the range is enormous and varied. Many develop sexually at an early age. Others are late developers, and often they may reach the age of 18 or 20 before some of the typical secondary sexual characteristics (as the doctors say) have appeared. This is especially so in regard to breast development.
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Womens health
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