Taboo and Genetics Part 2

A modern version of this old belief was the idea advanced by Harvey that the ovum consisted of fluid in which the embryo appeared by spontaneous generation. Loeuwenhoek's development of the microscope in the 17th century led immediately to the discovery of the spermatozoon by one of his students. At the time, the "preformation theory" was probably the most widely accepted--i.e., that the adult form exists in miniature in the egg or germ, development being merely an unfolding of these preformed parts. With the discovery of the spermatozoon the preformationists were divided into two schools, one (the ovists) holding that the ovum was the container of the miniature individual, the other (animalculists) according this function to the spermatozoon. According to the ovists, the ovum needed merely the stimulation of the spermatozoon to cause its contained individual to undergo development, while the animalculists looked upon the spermatozoon as the essential embryo container, the ovum serving merely as a suitable food supply or growing place.

This nine-lived notion of male supremacy in inheritance was rather reinforced than removed by the breeding of domestic animals in the still more recent past. Attention has been focused on a few great males.

For example, the breed of American trotting horses all goes back to one sire--Hambletonian 10. The great Orloff Stud Book, registering over a million individuals, is in the beginning founded on a single horse--a male. It is not strange that we still find among some breeders vestiges of the ancient belief that the male predominates in inheritance. A superior male can impress his characters in a single year upon 100 times as _many_ colts as a female of equal quality could produce in her lifetime. So slight an incident in his life is this reproductive process for each individual that he could if he devoted his life solely to reproduction stamp his characters upon a thousand times as many colts as could a female. Thus under artificial breeding conditions, the good males do have a tremendously disproportionate share in improving the whole breed of horses, though each single horse gets his qualities equally from his male and female parents.

Though Mendel knew an astonishing amount about inheritance a half-century ago, it is worth noting that the foundation upon which rests our present knowledge of s.e.x has been discovered less than twenty years before--the reference is, of course, to the chromosomes as the carriers of inheritance. While from the standpoint of biology the opinions of two decades ago about s.e.x literally belong to a different age, some of them have been so persistent in sociological thought and writings that they must be briefly reviewed in order that the reader may be on his guard against them. Books which still have a wide circulation deal with the s.e.x problem in terms of a biology now no more tenable than the flatness of the earth.

On the one hand were the ancient traditions of male predominance in inheritance, reinforced by the peculiar emphasis which animal breeding places upon males. On the other hand, biologists like Andrew Wilson[5]

had argued as early as the seventies of the past century for female predominance, from the general evidence of spiders, birds, etc. Lester F. Ward crystallized the arguments for this view in an article ent.i.tled "Our Better Halves" in _The Forum_ in 1888. This philosophy of s.e.x, which he christened the "Gynaecocentric Theory," is best known as expanded into the fourteenth chapter of his "Pure Sociology," published fifteen years later. Its publication at this late date gave it an unfortunate vitality long after its main tenets had been disproved in the biological laboratory. Germ-cell and body-cell functions were not separated. Arguments from social structures, from cosmic, natural and human history, much of it deduced by a.n.a.logy, were jumbled together in a fashion which seems amazing to us now, though common enough thirty years ago. It was not a wild hypothesis in 1888, its real date, but its repeated republication (in the original and in the works of other writers who accepted it as authoritative) since 1903 has done much to discredit sociology with biologists and, what is more serious, to muddle ideas about s.e.x and society.

In 1903, Weismann's theory of the continuity of the germplasm was ten years old. De Vries' experiments in variation and Mendel's rediscovered work on plant hybridization had hopelessly undermined the older notion that the evolution or progress of species has taken place through the inheritance of acquired characters--that is, that the individuals developed or adapted themselves to suit their surroundings and that these body-modifications were inherited by their offspring. As pointed out in Chapter I, biologists have accepted Weismann's theory of a continuous germplasm, and that this germplasm, not the body, is the carrier of inheritance. n.o.body has so far produced evidence of any trace of any biological mechanism whereby development of part of the body--say the biceps of the brain--of the individual could possibly produce such a specific modification of the germplasm he carries as to result in the inheritance of a similar development by his offspring.

Mendel's experiments had shown that the characters we inherit are units or combinations of units, very difficult to permanently change or modify. They combine with each other in all sorts of complicated ways.

Sometimes one will "dominate" another, causing it to disappear for a generation or more; but it is not broken up. These characters have a remarkable way of becoming "segregated" once more--that is, of appearing intact later on.

While it follows from Weismann's theory that an adaptation acquired by an individual during his lifetime cannot be transmitted to his offspring, it remained for De Vries to show authoritatively that evolution can, and does, take place without this. Once this was established, biologists cheerfully abandoned the earlier notion. Lester Ward and the biologists of his day in general not only believed in the transmission of acquired characters, but they filled the obvious gaps which occurred in trying to apply this theory to the observed facts by placing a fantastic emphasis upon s.e.xual selection. That is, much progress was accounted for through the selection by the females of the superior males. This, as a prime factor in evolution, has since been almost "wholly discredited" (Kellogg's phrase) by the careful experiments of Mayer, Soule, Dougla.s.s, Durigen, Morgan and others. The belief in s.e.xual selection involved a long string of corollaries, of which biology has about purged itself, but they hang on tenaciously in sociological and popular literature. For instance, Ward believed in the tendency of opposites to mate (tall men with short women, blonds with brunettes, etc.), although Karl Pearson had published a statistical refutation in his _Grammar of Science_, which had run through two editions when the _Pure Sociology_ appeared. The greater variability of males than females, another gynaecocentric dogma had also been attacked by Pearson on statistical evidence in 1897 (in the well-known essay on Variation in Man and Woman, in _Chances of Death_) and has become increasingly unacceptable through the researches of Mrs.

Hollingworth[6,7,8]. The idea of a vanished age of mother-rule in human society, so essential to the complete theory, has long since been modified by anthropologists.

De Vries' experiments showed that a moderately simple fact practically makes all these complicated theories unnecessary. No two living things are exactly alike--that is, all living matter is more or less variable.

Some variations are more fortunate than others, and these variants are the ones which survive--the ones best adapted to their environment.

Given this fact of the constant variation of living matter, natural selection (i.e., survival of the fittest and elimination of the unfit) is the mechanism of evolution or progress which best accounts for the observed facts. Such variation is called "chance variation," not because it takes place by "chance" in the properly accepted sense of the term, but because it is so tremendously varied--is evidently due to such complicated and little-understood circ.u.mstances--that it can best be studied mathematically, using statistical applications of the "theory of probabilities."

The fine-spun, elaborate theories about s.e.x, so current twenty years ago, have fallen into almost complete desuetude among scientists. With the discovery of the place of the chromosomes in inheritance, biologists began to give their almost undivided attention to a rigid laboratory examination of the cell. This has included s.e.x phenomena since McClung and Sutton pointed out the function of the s.e.x chromosome in 1902 and 1903. Present-day "theories" are little more than working hypotheses, developed, not in a library or study, but with one eye glued to a high-power microscope.

Besides its faulty foundation as to facts, the old gynaecocentric theory involved a method of treatment by historical a.n.a.logy which biologists have almost entirely discarded. Anyone interested in the relative value of different kinds of biological data for social problems would do well to read the opening chapter of Prof. Morgan's "Critique of the Theory of Evolution"[9], for even a summary of which s.p.a.ce is lacking here.

College reference shelves are still stocked with books on s.e.x sociology which are totally oblivious of present-day biology. For example, Mrs Gilman (Man-Made World), Mrs Hartley (Truth About Woman) and the Nearings (Woman and Social Progress) adhere to Ward's theory in substantially its primitive form, and not even sociologists like Professor Thomas (s.e.x and Society) have been able to entirely break away from it.

The old question of male and female predominance in inheritance has been to a considerable extent cleared up, to the discomfiture of both sides to the controversy. Most exhaustive experiments failed to trace any characters to any other part of either sperm or egg than the nucleus.

Transmission of characteristics seemed to be absolutely equal by the two parents. The male nucleus enters the egg practically naked. Hence if the characters are transmitted equally, there is certainly ground for supposing that only the nucleus of the egg has such functions, and that the remainder merely provides material for early development. Yet this does not seem to be strictly true.

Parthenogenesis (development of eggs without agency of male sperm) proves that in many simple forms the female nucleus alone possesses all the essential determiners for a new individual. Boveri's cla.s.sic experiment[10] proved the same thing for the male nucleus. He removed the nuclei from sea-urchin eggs and replaced them with male nuclei.

Normal individuals developed. To make things still more certain, he replaced the female nucleus with a male one from a different variety of sea-urchin. The resulting individual exhibited the characteristics of the _male nucleus_ only--none of those of the species represented by the egg. Here, then, was inheritance definitely traced to the nucleus. If this nucleus is a male the characters are those of the male line; if a female those of the female line, and in s.e.xual reproduction where the two are fused, half and half.

Yet the fact remained that all efforts to develop the spermatozoon alone (without the agency of any egg material at all) into an individual had signally failed. Conklin[11] had found out in 1904 and 1905 that the egg cytoplasm in Ascidians is not only composed of different materials, but that these give rise to definite structures in the embryo later on. So a good many biologists believed, and still believe[12,13,14] that the egg is, before fertilization, a sort of "rough preformation of the future embryo" and that the Mendelian factors in the nuclei "only impress the individual (and variety) characters upon this rough block."

If we look at these views from one angle, the apparent conflict disappears, as Professor Conklin[15] points out. We can still presume that all the factors of inheritance are carried in the nucleus. But instead of commencing the life history of the individual at fertilization, we must date it back to the beginning of the development of the egg in the ovary. Whatever rude characters the egg possesses at the time of fertilization were developed under the influence of the nucleus, which in turn got them half and half from its male and female parents. These characters carried by the female across one generation are so rudimentary that they are completely covered up, in the developing embryo, by those of the new nucleus formed by the union of the sperm with the egg in fertilization.

In case fertilization does not take place, this rude beginning in the egg is lost. Since no characteristic s.e.x is a.s.sumed until after fertilization, we may say that life begins as neuter in the individual, as it is presumed to have done in the world. It will occur to those inclined to speculation or philosophic a.n.a.lysis that by the word "neuter" we may mean any one or all of three things: (a) neither male nor female; (b) both male and female, as yet undifferentiated, or (c) potentially either male or female. Clearly, the above explanation a.s.sumes a certain _germinal_ specialization of the female to reproduction, in addition to the body specialization for the intra-parental environment (in mammals).

A tremendous amount of laboratory experimentation upon animals has been done in late years to determine the nature of s.e.x. For example, Goodale[16] castrated a brown leghorn c.o.c.kerel twenty-three days old and dropped pieces of the ovary of a female bird of the same brood and strain into the abdominal cavity. These adhered and built up circulatory systems, as an autopsy later showed. This c.o.c.kerel, whose male s.e.x glands had been exchanged for female ones, developed the female body, and colouration so completely that expert breeders of the strain p.r.o.nounced it a female. He found that simply removing the female s.e.x glands invariably led to the development of spurs and male plumage. But simple removal of the male s.e.x glands did not alter plumage. To make sure, he replaced the male s.e.x glands with female, and found that the former male developed female plumage.

This obviously signifies that in birds the female is an inhibited male.[4, p.49.] Either s.e.x when castrated has male feathers--the male has them either with or without testes, unless they are _inhibited_ by the presence of (transplanted) ovaries. It will be remembered that the sociological theory of s.e.x held by Ward, Mrs. Hartley and a host of others was founded on the supposition that evolution or development of a species is chiefly due to selection by the females of the better males, a conclusion based almost entirely on bird evidence. Ward[17] states that "the change or progress, as it may be called, has been wholly in the male, the female remaining unchanged"; also that "the male side of nature shot up and blossomed out in an unnatural, fantastic way...."

Speaking of the highly-coloured males, especially among birds, the same writer states that "the _normal colour_ (italics ours) is that of the young and the female, and the colour of the male is the result of his excessive variability." Goodale's results completely refute this idea, and should bury for ever the well-known sociological notion of "male afflorescence."

The general doctrine of a stable, "race-type" female and a highly variable male has been widely circulated. In tracing it back through voluminous literature, it appears to have been founded on an article published by W.I. Brooks in the _Popular Science Monthly_ for June, 1879, fourteen years before Weissmann's enunciation of the theory of continuity of the germ-plasm. Like Wallace, Brooks continued to study and experiment till the last, and finally withdrew from his earlier position on s.e.xual selection. However, this has not prevented others from continuing to quote his discarded views--innocently, of course.

Havelock Ellis[18] and G. Stanley Hall[19] have applied the idea of a "race-type" female with peculiar insistence to the human race. Goodale has finally killed the bird evidence upon which earlier workers so largely founded this doctrine, by showing that the "race type" toward which birds tend unless inhibited by the female ovarian secretion is the male type, not the female. There is a great difference in the way the internal secretions act in birds and in man, as will be pointed out later. It is so important that such a major point as general variability must be supported and corroborated by mammalian evidence to prove anything positively for man. As already noted, the statistical studies of Pearson and Mrs. Hollingworth _et al._ have yielded uniformly negative results.

In the utilization of data gathered from non-human species, certain differences in the systems of internal secretion must be taken into account. Birds differ from the human species as to internal secretory action in two vital particulars: (a) In the higher mammals, s.e.x depends upon a "complex" of all the glands interacting, instead of upon the s.e.x glands alone as in birds; (b) The male bird instead of the female is h.o.m.ogametic for s.e.x--i.e., the sperm instead of the eggs is uniform as to the s.e.x chromosome.

Insects are (in some cases at least) like birds as to the odd chromosome--the opposite of man. But as to secondary s.e.x-characters they differ from both. These characters do not depend upon any condition of the s.e.x organs, but are determined directly by the chemical factors which determine s.e.x itself.[20]

In crustacea, the male is an inhibited female (the exact opposite of birds), as shown by the experiments of Giard and Geoffrey Smith on crabs. A parasite, _Sacculina neglecta_, sometimes drives root-like growths into the spider crab, causing slow castration. The females thus des.e.xed do not a.s.sume the male type of body, but castrated males vary so far toward the female type that some lay eggs[3, p.143; 20]. It is the discovery of such distinctions which makes it necessary to re-examine all the older biological evidence on the s.e.x problem, and to discard most of it as insufficiently exact.

The work of Steinach[12, pp.225f.] on rats is another well-known example of changing s.e.x characters by surgery. Steinach found that an ovary transplanted into a male body changed its characteristics and instincts into the female type. The growth of the male s.e.x organs he found to be definitely inhibited by the ovaries. He went so far as to transplant the whole uterus and tube into the male body, where it developed normally.

One of the most interesting of his results is the observation of how the instincts were changed along with the type of body. The feminized males behaved like normal females toward the other males and toward females.

Likewise they were treated as normal females by the males.

It would be impossible to give here any just idea of the vast amount of rigid scientific experimentation which has been carried on in this field, or the certainty of many of the results. s.e.x is really known, about as well as anything can be known, to arise from the chemical causes discussed above. That is, the endocrine explanation is the correct one.

One of the most significant results of the transplantation experiments is the evidence that _each individual carries the fundamental bases for both s.e.xes_. When Goodale changed a male bird into a female as to secondary characters and instincts by replacing one secretion with another, he was faced with the following problem: How can a single secretion be responsible for innumerable changes as to feather length, form and colouring, as to spurs, comb and almost an endless array of other details? To suppose that a secretion could be so complicated in its action as to determine each one of a thousand different items of structure, colour and behaviour would be preposterous. Besides, we know that some of these internal secretions are _not_ excessively complicated--for instance adrenalin (the suprarenal secretion) can be compounded in the laboratory. We may say that it cannot possibly be that the ovarian or testicular secretion is composed of enough different chemical substances to produce each different effect.

There remains only the supposition that the female already possesses the genetic basis for becoming a male, and _vice versa_. This is in accord with the observed facts. In countless experiments it is shown that the transformed female becomes like the male of her own strain and brood--to state it simply, like the male she would have been if she had not been a female. If we think of this basis as single, then it must _exhibit_ itself in one way in the presence of the male secretions, in another way under the influence of the female secretions. In this way a very simple chemical agent in the secretion might account for the whole difference--merely causing a genetic basis already present to express itself in the one or the other manner.

This may be ill.u.s.trated by the familiar case of the crustacea _Artemia salina_ and _Artemia Milhausenii_. These are so unlike that they were long supposed to be different species; but it was later discovered that the genetic basis is exactly the same. One lives in 4 to 8% salt water, the other in 25% or over. If, however, the fresh-water variety is put in the saltier water with the salt-water variety, all develop exactly alike, into the salt-water kind. Likewise, if the salt-water variety is developed in fresh water, it a.s.sumes all the characteristics of the fresh-water kind. Thus the addition or subtraction of a single chemical agent--common salt--makes all the difference.

If this basis for s.e.x is single, it is represented by the male plumage in domestic birds, the secretions from the s.e.x-glands acting as modifiers. But a great deal of evidence has been produced to show that the genetic basis, in man and some other forms at least, is double. That is, we must think of two genetic bases existing in each individual--each representing one of the two types of secondary s.e.x characters. The primary s.e.x (i.e., the s.e.x glands) would then determine which is to express itself. In the domestic birds described above, the male type of body appears in the absence of the ovarian secretion, and the female type in its presence. In man and the more highly organized mammals, we must use "secretions" in the plural, since a number of them, from different glands, act together in a "complex." Goodale, experimenting with birds, was unable to definitely decide whether the basis for s.e.x was single or double in that material, though he favoured the latter explanation.

Dr Bell, the English gynecologist, using human surgical cases as a basis, commits himself strongly to the dual basis.[2, p.13.] "Every fertilized ovum," he says, "is potentially bis.e.xual," but has "a predominating tendency ... toward masculinity or femininity." But "at the same time," he remarks, "it is equally obvious that latent traits of the opposite s.e.x are always present." After discussing mental traits observed in each s.e.x which normally belong to the other, he concludes as follows: "If further evidence of this bis.e.xuality, which exists in everyone, were required, it is to be found in the embryological remains of the latent s.e.x, which always exist in the genital ducts."

In some lower forms, dual s.e.xuality is apparent until the animal is fairly well developed. In frogs, for example, the s.e.x glands of both s.e.xes contain eggs in early life, and it is not possible to tell them apart with certainty, until they are about four months old.[12, p.125.]

Then the eggs gradually disappear in the male.

However, we need not depend upon non-mammalian evidence for either the secretory explanation or the dual basis. An ideal case would be to observe the effects of circulating the blood of one s.e.x in a developing embryo of the other. This blood-transfusion occurs in nature in the "Free-Martin" cattle.[21]

Two embryos (twins) begin to develop in separate membranes or chorions.

At an early stage in this development, however, the arteries and veins of the two become connected, so that the blood of each may circulate through the body of the other. "If both are males or both are females no harm results from this...," since the chemical balance which determines the bodily form in each case is of the same type. But if one is a male and the other a female, the male secretory balance dominates the female in a very peculiar fashion. The female reproductive system is largely suppressed. She even develops certain male organs, and her general bodily appearance is so decidedly masculine that until Dr Lillie worked out the case she had always been supposed to be a non-functional male.

She is sterile. The blood transfusion not only alters the s.e.x-type of her body, but it actually modifies the s.e.x glands themselves, so that the ovary resembles a t.e.s.t.i.c.l.e, though dissection proves the contrary.

Why does not the female become a true, functional male? Perhaps she does in some cases. Such a one would not be investigated, since there would be no visible peculiarity. In all the cases examined, the embryo had begun its female development and specialization under the influence of a predisposition of the female type in the fertilized egg, before the transfusion began. There is no absolutely convincing mammalian evidence of the complete upset of this predisposition, so all one can say is that it is theoretically possible. Cases of partial reversal, sometimes called "inters.e.xes," are common enough. In birds and insects, where the material is less expensive and experimentation simpler, males have been produced from female-predisposed fertilized eggs and _vice versa_, as we shall see in the next chapter.

Dr Bell[2, pp.133f.] points out that the so-called human "hermaphrodites"

are simply partial reversals of the s.e.x type from that originally fixed in the fertilized egg. As has been remarked earlier in these pages, there is rarely if ever true hermaphroditism in higher animals--i.e., cases of _two functional s.e.xes_ in the same individual. In fact, the pathological cases in the human species called by that name are probably not capable of reproduction at all.[A]

[Footnote A: _Note on human hermaphroditism_: This subject has been treated in a considerable medical literature. See, for example, Alienist and Neurologist for August, 1916, and New York Medical Journal for Oct.

23, 1915. It has been claimed that both human and higher mammalian "hermaphrodites" have actually functioned for both s.e.xes. Obviously, absolute certainty about cause and effect in such cases, where human beings are concerned, is next to impossible, because of lack of scientific, laboratory control. If a case of complete functional hermaphroditism in the human species could be established beyond question, it would indicate that the male secretory balance in man does not inhibit the female organs to the same extent that it apparently does in the Free-Martin cattle. If established, the idea of "male dominance"

in the human species would be undermined in a new place. Such cases, if they occur at all, are exceedingly rare, but are of theoretical interest. We must not rush to conclusions, as the earlier sociologists used to do. Such a case would require careful a.n.a.lysis. Its very uniqueness would suggest that it may not be due to the ordinary causes of hermaphroditism, but might arise from some obscure and unusual cause such as the fusion of two embryos at a very early stage. The biochemistry involved is so intricate and so little understood that any deduction from the known facts would be purely speculative.]

Like the Free-Martin cattle, some accident has resulted in a mixture of male and female characteristics. This accident occurs after a certain amount of embryonic development has taken place under the influence of the original predisposition of the fertilized egg. The delicate secretory balance, so complex in man, is upset. With partially developed organs of one type and with a blood-chemistry of the opposite one, some curious results follow, as the ill.u.s.trative plates in Dr Bell's book show.

It should be remembered that s.e.x in higher mammals is of the whole body, and depends upon all the secretions. Hence an accident to one of the other glands may upset the balance as well as one to the s.e.x glands themselves. For example, 15% of Neugebauer's[22] cases of female tubular partial hermaphroditism had abnormal growths in the suprarenals.

Thus in the human species, it is possible for one type of s.e.x glands to exist in the opposite type of body, as we saw it to be in cattle--though it apparently could not occur unless compensated for in some way by the other secretions. This is a very great departure from birds, rats and guinea pigs, whose bodies change over their s.e.x type when the gonads are transplanted. Birds take on the male appearance when the s.e.x glands are removed (or retain it, if they are males). This is not true of man. The chemical life processes of the two s.e.xes after p.u.b.erty in the human species are quite characteristic. The male and female types are both very different from the infantile. When it becomes necessary to des.e.x men, the resulting condition is _infantile_, not female.[23]

The des.e.xed man is of course the eunuch of ancient literature. If des.e.xed near maturity, he might look like a normal man in many respects; but if the operation were performed before p.u.b.erty, his development is simply arrested and remains infantile--incomplete. Only in 1878 was the practice of des.e.xing boys to get the famous adult male soprano voices for the Sistine Choir discontinued.

Removal of the ovaries in women likewise produces an infantile condition, which is p.r.o.nounced only in case the operation takes place very young. [24] From his clinical experience, Dr Bell [2, p.160]

concludes that no very definite modifications can be produced in an adult woman by withdrawal of the ovarian secretion alone. "There must be," he says, "some gross change in those parts of the endocritic system, especially apart from the genital glands, which normally produce masculinity--potentiality that appears to be concentrated in the suprarenals, the pituitary and probably in the pineal."