What, then, do we mean by "male" and "female" in man? Take Dr Russell Andrews" patient: photographs[2, plate opposite p.243] show a rounded bodily outline, hairless face, well-developed mammae--the female s.e.x characteristics in every respect which the ordinary person could detect.
Yet an operation proved that the s.e.x glands themselves were male.
Presumably extreme cases like the above are rare. Obviously operations cannot be performed on all those with female-type bodies who do not bear children, to determine the primary s.e.x, and conversely with men. This does, however, point the obvious question: Are not some we cla.s.sify as men _more male_ or masculine than others--some we cla.s.sify as women _more feminine_ than others? Bearing in mind the fact that the genetic basis for both s.e.xes exists in each individual, are not some women more masculine than others, some men more feminine than others? However much we may object to stating it just that way, the biological fact remains thus. The Greeks called these intermediate types _urnings_--modern biology knows them as "inters.e.xes."
Only within the past few years have the general phenomena of inters.e.xuality been cleared up to any considerable extent--naturally on the basis of the secretory explanation of s.e.x. This secretory or endocrine idea has also given us an entirely new view of s.e.x differences. These are best discussed as functional rather than as structural. To correlate this material, we must next give a rude sketch of the quant.i.tative theory of s.e.x.
BIBLIOGRAPHY FOR CHAPTER II
1. Goldschmidt, R. Inters.e.xuality and the Endocrine Aspect of s.e.x.
Endocrinology, Vol. I, p. 434, 1917.
2. Bell, Dr Blair. The s.e.x Complex. London, 1916, p. 98.
3. Paton, D. Noel. Regulators of Metabolism. London, 1913, p. 146.
4. Goodale, H.D. Gonadectomy...Carnegie Pub. 243, 1916, pp. 43f.
5. Wilson, Andrew. Polity of a Pond (essay). Humboldt Lib. of Sc., No. 88--reprint, dated 1888.
6. Hollingworth, L.S. Variability as Related to s.e.x Differences in Achievement. Am. Jour, of Sociol., XIX., 1914, pp. 510-530.
7. Lowie, R.H. & Hollingworth, L.S. Science and Feminism. Sci. Mthly., Sept., 1916, pp. 277-284.
8. Montague, Helen & Hollingworth, L.S. Comparative Variability of the s.e.xes at Birth. Am. J. of Sociol. XX, 335-70. 1915.
9. Morgan, T.H. A Critique of the Theory of Evolution. N.Y., 1916, pp. 1-27.
10. Loeb, Jacques. Artificial Parthenogenesis and Fertilization.
Chicago, 1913, pp. 3, 51f., 240f, 303.
11. Conklin, E.G. Organ-Forming Substances in the Eggs of Ascidians.
U. of Pa. Contrib. from the Zool. Lab. Vol. 12. 1905, pp. 205-230.
12. Loeb, J. The Organism as a Whole. N.Y., 1916, pp. 138f, 151-2.
13. Guyer, M.F. Being Well-Born. Indianapolis, 1916, p. 51.
14. Tower, W.L. (et al.). Heredity and Eugenics. Chicago, 1912, pp. 164, 254-5.
15. Conklin, E.G. Share of Egg and Sperm in Heredity. Proc. Nat. Acad.
of Sc., Feb., 1917.
16. Goodale, H.D. A Feminized c.o.c.kerel. Jour. Exp. Zool. Vol. 20, pp. 421-8.
17. Ward, Lester F. Pure Sociology. N.Y., 1903, pp. 322f.
18. Ellis, Havelock. Man and Woman, 4th Ed. London, 1904. Ch. XVI.
19. Hall, G. Stanley. Adolescence. N.Y., 1907. Vol. II, pp. 561-2.
20. Morgan, T.H. Heredity and s.e.x. N.Y., 1913, pp. 155f.
21. Lillie, F.R. Theory of the Free Martin. Science, n.s., Vol. XLIII, pp. 611-13.
22. Neugebauer, F.L. Hermaphrodismus, Leipzig, 1908.
23. Vincent, S. Internal Secretions and the Ductless Glands. London, 1912, p. 69.
24. Marshall, F.H. Physiology of Reproduction. London, 1910, p. 314.
CHAPTER III
s.e.x AND s.e.x DIFFERENCES AS QUANt.i.tATIVE
Inters.e.xes in moths; Bird inters.e.xes; Higher metabolism of males; Quant.i.tative difference between s.e.x factors; Old ideas of inters.e.xuality; Modern surgery and human inters.e.xes; Quant.i.tative theory a Mendelian explanation; Peculiar complication in the case of man; Chemical life cycles of the s.e.xes; Functional-reproductive period and the s.e.x problem; Relative significance of physiological s.e.x differences.
Crossing European and j.a.panese gypsy moths, Goldschmidt [1,2,3,4]
noticed that the s.e.x types secured were not pure--i.e., that certain crosses produced females which bore a distinctly greater resemblance to the male type than others, and _vice versa_. One of these hybrids of "inters.e.xes," as he calls them, would always possess some female and some male s.e.xual characters. He found that he could separate the males and females, respectively, into seven distinct grades with respect to their modification toward the opposite-s.e.x type, and could produce any one of these grades at will by breeding.
For example, the seven grades of females were roughly as follows: (1) Pure females; (2) Females with feathered antennae like males and producing fewer than the normal number of eggs; (3) Appearance of the brown (male) patches on the white female wings; ripe eggs in abdomen, but only hairs in the egg-sponge laid; instincts still female; (4) Instincts less female; whole sections of wings with male colouration, interspersed with cuneiform female sectors; abdomen smaller, males less attracted; reproduction impossible; (5) Male colouration over almost the entire wing; abdomen almost male, with few ripe eggs; instincts intermediate between male and female; (6) Like males, but with rudimentary ovaries and show female traits in some other organs; (7) Males with a few traces of female origin, notably wing-shape.
The males showed the same graded approach to the female type. Their instincts likewise became more and more female as the type was modified in that direction. That is, a moth would be 12% or 35% female, and so on.
Goldschmidt watched the crosses which produced seven different grades of maleness in his females. The moth material, like the birds and mammals, suggested a dual basis for s.e.x in each individual. The grades of maleness and femaleness made it seem probable that the factor which determines s.e.x must be stronger in some instances than in others, i.e., that the difference between two of these grades of female is originally quant.i.tative, not qualitative--in amount rather than in kind.
Mating European moths with European, or j.a.panese with j.a.panese, produced pure, uniform s.e.x-types, male and female. But a cross of European with j.a.panese strains resulted in inters.e.xes. Goldschmidt concluded that (1) all individuals carried the genetic basis for both s.e.xes; and (2) that these basic factors were two chemicals of enzyme nature. One of these he called Andrase, enzyme producing maleness, the other Gynase, enzyme producing femaleness. Further, (3) since each chemical s.e.x determiner is present in both individuals in every cross, there must be two chemical "doses" of maleness and two of femaleness struggling for mastery in each fertilized egg. (4) If the total dose of maleness exceeds the total dose of femaleness, the s.e.x will be male, and _vice versa_. (5) These quant.i.ties get fixed by natural selection in a single race which always lives in the same environment, i.e., the doses of maleness and femaleness in a given s.e.x always bear practically the same relation to each other. Hence the types are fixed and uniform.
(6) But different races are likely to have a different strength of chemical s.e.x-doses, so that when they are crossed, the ratios of maleness to femaleness are upset. Often they are almost exactly equal, which produces a type half male and half female--or 2/3, or 1/3, etc.
The proof of this theory is that it solved the problems. Goldschmidt was able to work out the strengths of the doses of each s.e.x in his various individuals, and thereby to predict the exact grade of inters.e.xuality which would result from a given cross.
Riddle"s work on pigeons [5,6] brings us much nearer to man, and suggests the results noted by both Goldschmidt and Lillie. As in the Free-Martin cattle, there is an apparent reversal of the s.e.x predisposition of the fertilized egg. As in the gypsy moths, different grades of inters.e.xes were observed. In the pigeons, it was found that more yolk material tended to produce a larger proportion of females. The most minute quant.i.tative measurements were made of this factor, to eliminate any possibility of error.
The chromosome mechanisms practically force us to suppose that about half the eggs are originally predisposed to maleness, half to femaleness. A pigeon"s clutch normally consists of two eggs, one with a large yolk and one with a small yolk. But the half-and-half numerical relation of males to females varies considerably--i.e., not all the large-yolked eggs produce females or all the small-yolked ones males.
Wild pigeons begin the season by throwing a predominance of males, and the first eggs of the clutches also tend to produce males all along. In both cases, the male-producing eggs were found to be the ones with the smaller yolks. Family crosses also produce small yolks, which hatch out nearly all males. Some pairs of birds, however, have nearly all female offspring. Riddle investigated a large number of these cases and found the amount of yolk material to be large. In other words, there seems to be a definite relation between the amount of yolk and s.e.x.
A great number of clever experiments were carried out to find out if eggs originally predisposed to one s.e.x were actually used to produce the other. Selective fertilization with different kinds of sperm was impossible, since in these birds there is only one type of sperm--two of eggs--as to the s.e.x chromosome. For instance, by overworking females at egg-production, the same birds which had been producing more males than females were made to reverse that relation.
One of the interesting results of the experiments was the production of a number of inters.e.xual types of various grades. This was easily verifiable by colour and other characteristics. To make sure that the instincts were correspondingly modified, behaviour was registered on moving-picture films. Where the first egg of a clutch (the one with a small, normally male-producing yolk) produces a female, she is usually found to be more masculine than her sister from the second egg with the larger yolk. This is true both as to appearance and as to behaviour.
Some of these were quite nearly males in appearance and behaviour, though they laid eggs.
Testicular and ovarian extracts were injected. The more feminine birds were often killed by the testicular extract, the more masculine by the ovarian extract. Finally, to make a.s.surance doubly sure, some females which should theoretically have been the most feminine were dissected and shown to be so. That is, out-crosses which produced a predominance of females in the fall were mated with females which had been overworked at egg production until they threw nearly all females. Dissecting the females thus produced, they were shown to have _right ovaries_, which means _double femaleness_, since normally the pigeon is functional only in the left ovary, like other birds. The right one usually degenerates before or at hatching and is wholly absent in the week-old squab.
In pigeons, Riddle thinks the "developmental energy" of the eggs is in an inverse ratio to their size. The last and largest eggs of the season develop least and produce most females. The second egg of a clutch is larger than the first, but develops less and the bird produced is shorter-lived. Overworking and other conditions tending to produce large eggs and females also throw white mutants and show other signs of weakness. Old females lay larger eggs than do young ones. These eggs produce more females. They store more material, have a lower metabolism and less oxidizing capacity than do the earlier male-producing eggs.