A powerful jaw, and perhaps also those mental qualities which are correlated with such a jaw, are of less primary importance under the conditions of civilised than of savage and barbarous life. The tendency of civilisation is to decrease the number and size of the teeth, and to decrease the size, and often to deform the bony cavity, of the mouth. 8 The question arises whether men or women show 1 Med Times, 9th January 1875.
* See, for instance, Oakley Coles, Deformities of the Mouthy p. 34* Google THE HEAD. 87 in a more marked way this progressive evolution or dissolution. There are marked sexual differences in the teeth of anthropoid apes: are there any traces of sexual difference in the teeth of man? Burdach considered that the teeth of women are smaller than those of men, that the wisdom teeth are more frequently absent or late in appearance, that the first teeth are more frequently preserved, and that those of the second dentition are more frequently late in appearance. 1 It cannot be said that all these state- ments have been decisively confirmed, although many of them are probably correct That the jaws of women have a marked tendency to be defective in size and consequently to cramp the teeth, there is much evidence to show. Mr. C. S. Tomes, F.R.S., writes in a private letter: " Speaking from a general impression, which, as you know, is nearly valueless in such a matter, I should say that contracted dental arches necessitating the extraction of teeth for space are commoner in female than in male children." But this argues no defect in the teeth themselves.
So far from the wisdom teeth being of later appear- ance in women, Magitot has shown by an examination of the wisdom teeth in 241 men and 259 women that they are more precocious in women than in men in France, the maximum number appearing at 22 years, in men at 23 years, — although at 25 years there happened to be 10 women to 6 men. 2 On the other hand, Ottofy found by an examination of over 600 boys and girls (in about equal numbers) that dental caries is more common in females than in males, both as regards temporary and permanent teeth. " At all ages during the eruptive period caries was more prevalent, on an average, among females than among 1 Physiologic > tome i. p. 306. (Here and elsewhere I quote from the French translation.) It has been noticed by Mondiere in his Monographic dc la Fcmtnc Annamitc that among the young girls of Annam the temporary teeth do not readily fall out, so causing defects in the second teeth.
8 Bull. Soc. d 1 Anthropologic dc Paris, 20 Fev. 1879.
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males by 5 per cent The proportionate ratio is about the same during the eleven years of life covered by these statistics." 1 Mr. J. S. Turner, on behalf of the British Dental Association, presented to the London (1891) meet- ing of the International Congress of Hygiene a communication giving the results of examination of a large number of school children. He showed that boys lost more teeth than girls. This would indicate that the teeth of girls are stronger or less subject to caries than those of boys. Dr. Galippe, it is true, found that the density of teeth is greater in men than women, but his observations, as he himself points out, were not very numerous, and the highest density he found happened to be in a woman. 2 We owe to Professor Flower a dental index which is constructed by multiplying the dental length by 100, and dividing by the basio-nasal length (or length from the naso-frontal suture to the edge of the foramen magnum). He finds that the white races are microdont (possessing, that is, small teeth and a small dental index); the yellow races are mesodont; the black races megadont, with large teeth and a large dental index, while among the anthropoid apes the dental indices are still larger. Among the apes the dental index among females is always greater than among males. A similar sexual difference is seen in the human species, the teeth in women more nearly retaining their size while the cranium with the body generally is less. The difference is, however, slight among European races.
Schaaffhausen has shown that the two upper middle front or incisor teeth are in women and girls not only relatively but absolutely larger than in men and boys of the same age. Comparing 50 girls to 50 boys of the ages of 12 to 15, he found that the average breadth of the teeth in question was as 1.33 in girls to I in 1 " Incipiency of Dental Caries," Dental Cosmos^ Jan. 1889. 8 Comptcs-Rendus de la Soctiti dc Biologic 1881, p. 290.
Google THE HEAD. 89 boys. Among 12 men belonging to Zandvoort, in Holland, he found an average breadth of 8.3, while 12 women gave a breadth of 8.8. In some women the teeth in question are conspicuously large. 1 We see therefore that while the jaws of women may in civilised races tend to be unduly small, there is some reason to believe that their teeth are relatively and even absolutely larger than those of men.
Cranial Capacity, — A considerable amount of attention has been given to the question of sexual differences in cranial capacity, but the results have been small. In nearly every large series of skulls, ancient or modern, savage or civilised, the cranial capacity is found to be considerably greater in men than in women. But when we consider that the body-weight is also considerably greater in men this result is not surprising, and while some anthropologists have asserted that the cranial capacity of men is relatively somewhat greater than that of women, others have been at least equally justified in deciding that the cranial capacity of women is relatively greater than that of men. At the best, cranial capacity is but a rough indication of brain size; and to measure brain size by the external size of the skull furnishes still rougher and more fallacious approximations, since the male skull is more massive than the female. 2 A point of some interest, which was noted long ago by Retzius, 8 and has since often been 1 See Ploss and Max Bartels, Das Weib, Bd. i. p. 15.
8 It is worth noting that woman's skull constitutes a larger part of the total bonv skeleton than man's. Thus Manouvrier's cranio-femoral index gives the relation of the weight of the thigh-bones to that of the skull, the latter equalling 100. Most women (83 per cent.) have heavier skulls than thigh-bones; in most men (81 per cent.) the thigh- bones are heavier. From this point of view the relative size of the skull diminishes in the following order: child, woman, short man, tall man, ape.
• Muiler's Archiv. fur Anat.> 1845, p. 89; and see Rolleston's Presidential Address to Anthropological Section, Brit. Association, 1875; also Le Bon, Revue (VAnth^ 1879, p. 56.
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raised, is the relative sexual difference in the higher and in the lower races; it is a question whether in the higher races there are not greater sexual differ- ences than in the lower races. I have prepared the following table bearing on this point, using many of the figures obtained by Weisbach, and also working out the proportions given by Topinard, Flower's as harmonised by Topinard, and adding others from different sources. 1 The figures give the average cranial capacity of woman's skull if the man's be taken to equal iooo.
Negro (Davis), 984. Bushman (Flower), 951. Hottentot and Bushman Hindu (Davis), 944. Negro (Tiedemann), 932. Eskimo (Broca), 931. Australian (Broca), 926. Malay (Tiedemann), 923. Dutch (Tiedemann), 919. Irish (Davis), 912. Andaman (Flower), 911. New Caledonian (Broca), 91 1. Dutch (Broca), 909. Tasmanian (Broca), 907. Kanaka (Davis), 906. Veddah (Davis, Flower, Virchow, Thomson), 903. Marquisas (Davis), 902. German (Welcker), 897. Auvergnat (Broca), 897.
German, town-dwelling Australian (Flower), 889. German, country-dwelling Russian (Popow), 884. German (Davis), 883. German (Weisbach), 878. Ancient British (Davis), S77. Javanese (Tiedemann), 874. Chinese (Davis), 870. German (Tiedemann), 864. Anglo-Saxon (Davis), 862. Parisian of 12th century English (Davis), 860. Parisian of 19th century Javanese (Broca), 855. Eskimo (Flower), 855. German (Huschke), 838.
This table brings out very clearly on the whole the gradual sexual divergence in cranial capacity under the influence of evolution and civilisation. There are naturally many discrepancies, due to some of the series included being too small, or abnormal, or to difference in methods of measurement. Thus if from the series of Veddah skulls two were to be 1 Weisbach, "Der deutsche Weiberschadel," Archiv. fiir Anth^ Bd. iii., 1868; Topinard, VHomme> etc., 1891, p. 218.
Google THE HEAD. 9 1 omitted — an abnormally large masculine and an abnormally small feminine — it would be found that the Veddahs, a very primitive race, would come at the top of the list, where they perhaps belong. We may divide them all into two groups, those races among whom the female skull is to the male as more than 900 to iooo, and those among whom it is less. In the first group there are only two races whom we are surprised to find, the Dutch and the Irish; the Dutch may stand, being supported by two authorities; the Irish are more dubious. In the second group, also, only two races seem out of place, the Australians and the Eskimo, and both of these are by other observers placed in the first group.
There are at least two great factors which work for large cranial capacity — large size of body and mental activity — which are both at work in civilisation. Among the small Maravers of southern India the cranial capacity of the women is, even absolutely, rather greater than that of the men; among the large-bodied Germans the cranial capacity of the women is relatively very small. Town-dwellers have a larger cranial capacity than country-dwellers, but the muscular labour undergone by country-dwellers keeps their cranial capacity at a fairly high level; Ranke found that while the minimum of 100 large- headed male town-folk was as low as 12 18, the minimum of 100 smaller-headed male country-folk was 1260. 1 The town-dweller without either manual or mental work falls very low, and in civilisation both the heaviest manual and the heaviest mental work falls to men. It is perhaps worth noting that Jacobs and Spielman found that while West End Jewesses are distinctly inferior to West End Jews in cranial measurements, there is comparatively little difference between East End Jews and Jewesses. It must be realised, however, that there are very distinct Google 92. MAN AND WOMAN.
limits to the equalisation of cranial characters by the equalisation of social conditions. Among orangs and gorillas the sexual cranial differences are enormous. The Australians are almost the lowest of human races, and live under the simplest conditions, but, as Turner remarks, examining the Challenger skulls, "The sexual characters were strongly marked in the Australian crania. The much smaller size and capacity of the female skull, its comparative light- ness, the feebleness of its ridges and processes, more especially the glabella; its low basi-bregmatic height and the high orbital index, all constituted important features of difference between the female and the male skulls." The relatively greater difference in cranial capacity among civilised than among savage races does not seem unexplainable, but it remains a fact of some interest and significance.
It has often been asserted, and more especially in the earlier days of craniology, that the frontal regions of the skull, regarded as the "nobler" regions, are more developed in men than in women. There is, however, no reason for supposing that the frontal region is higher or more characteristically human than any other cranial region; and there is just as little reason for supposing that the frontal region is more highly developed in men. Cleland, who com- pared the three regions of the skull — frontal, parietal, and occipital — in men and women, could find no noteworthy difference. Manouvrier, who has made the most extensive and reliable investigations on this point, found, by the examination of Broca's registers, that the frontal curve is relatively larger in women than in men in 14 series of skulls out of 17; that the parietal curve was relatively larger in women in 6 out of 17 series. He, therefore, came to the con- clusion that women exhibit a frontal type of skull, men a parietal type. 1 That the occipital region is 1 Manouvrier, " Sur la grandeur du Front et des principales regions du crane chez l'Homme et chez la Femme," Bull, de VAss. /ran.
Google THE HEAD. 93 also relatively larger in women has been found as well by Manouvrier as by Weisbach, who in his careful investigations of the German skull came to the conclusion that there is greater height and length in the occipital skull in women with equal breadth. Topinard's figures of the relative breadth of the different regions of the head in Parisian men and women show little or no superiority of breadth of the frontal region in women, but a very markedly greater breadth of the posterior region of the head, indicat- ing large size of occipital lobes and cerebellum. As Topinard points out, as a rule this breadth is greatest in the superior races; " the cephalic index of Russians and Javanese is almost the same, but the former, a higher race, have greater occipito-cerebellar breadth; the Basques have, almost to a decimal, the cephalic index of the Tasmanians, but they have greater occipital breadth'; Parisian men have only two units of cephalic index more than Parisian women, but the latter have eight units more of occipital breadth." 1 On the whole, we have found no valid ground for concluding from an examination of the skull that one sex is morphologically superior to the other sex. The only well-marked and generally acceptable sexual cranial differences, so far as our present know- ledge extends, are those pointed out at the outset: in men the air-sinuses and muscular projections are pour Vavancemeni des Sci. f 1882, pp. 623-639. Also Art. "Sexe," Diet, des set. Anthrop.
It may be noted here that a high forehead is by no means, as commonly supposed, the necessary accompaniment of high mental capacity. In women Benedikt (Kran. u. Keph.> p. 125) is accustomed to regard it as an indication of convulsive degeneration, and he refers to the instinctive concealment by women of a high forehead by arrange- ment of hair.
1 Topinard, VAnth. Gen., p. 694. Wilks (Lectures on Dis. Nervous System) remarks, "We have only to look at the head of a person with his faculties well developed to see a considerable projection behind, whilst in a person of low development the neck and head are in one line."
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more marked, and in women the bones are more prominent. In all three of these respects men approach the savage, simian, and senile type (for these, as we have seen, and as Virchow has pointed out, approximate to each other), while in all these respects also women approach the infantile type. It is open to a man in a Pharisaic mood to thank God that his cranial type is far removed from the infantile. It is equally open to a woman in such a mood to be thankful that her cranial type does not approach the senile.
THE BRAIN.
The history of opinion regarding cerebral sexual difference forms a painful page in scientific annals. It is full of prejudices, assumptions, fallacies, over- hasty generalisations. The unscientific have had a predilection for this subject; and men of science seem to have lost the scientific spirit when they approached the study of its seat Many a reputation has been lost in these soft and sinuous convolutions. It is only of recent years that a comparatively calm and disinterested study of the brain has become in any degree common; and even to-day the fairly well ascertained facts concerning sexual differences in the brain may be easily summed up.
There is no doubt whatever that in European races (for of other races our knowledge is scanty) the absolute weight of the brain in man is consider- ably greater than in women. The following are some of the averages reached by some of the chief investigators in different countries, working on a large number of brains, most of the series com- prising many hundreds: — Google THE HEAD.
95 Grammes.
Difference.
Wagner f Men ' \ Women Huschke.
J Men I Women Broca..
j Men ' \ Women Topinard.
j Men ' \ Women Manouvrier /Men * "[Women It is clear that in Europe men possess absolutely larger brains than women. There is no doubt on this point. The difficulty has arisen at the next stage. Have men relatively larger brains than women? We have first to decide relatively to what we are going to compare the brain. Height has usually suggested itself as the most convenient term of comparison. It would be better, as Topinard suggests, to take the height of the body only, ignoring the legs, but, so far as I am aware, this is never done. It is not difficult to ascertain with fair accuracy the average height of a population, and it is evident that when we have brought the brain into relation with 1 These figures were obtained from Boyd's well-known investigations at the Marylebone Infirmary, London. Sir James Crichton-Browne has obtained very similar results with the brains of the insane. From an examination of nearly sixteen hundred brains he found that the average in the male was 1 351 grammes, in the female 1223 grammes; the male average is a little lower than in the sane, on account of the serious nature of brain disease in men, and consequently in insanity the sexes approach each other in brain-weight more than in sanity. See Crichton-Browne " On the Weight of the Brain in the Insane," Brain, vols. i.-ii; also Clapham, Art. "Brain, Weight of, in the Insane," Diet. Psych. Med.; Tigges, "Das Gewicht des Gehirns und seine Theile bei Geisteskranken," Allgemein. Zeitschrift fur Psychiatric, vol.
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the stature we have made some approximation to a fair estimate. Relatively to stature, it is nearly always found that men still possess somewhat heavier brains than women. Thus, according to Boyd's average as well as Bischoffs, man's brain- weight is to woman's as ioo to 90; the average stature of men and women in England is as 100 to 93; so that, taking stature into account, men have a slight but distinct excess of brain (amounting, roughly speaking, to something over an ounce) over women. Precisely the same difference in ratio has been found in France. 1 On the strength of this ounce a distinguished brain anatomist has declared that "the difference, therefore, in the size and weight of the brain is obviously a fundamental sexual distinction," and the same assertion has often been made by others.
On consideration, however, it becomes clear that while it is very convenient, and even approximately correct, to estimate sexual differences in brain-mass relatively to sexual differences in body-height, it is not quite fair to women. Men are not only taller than women, they are larger. If human beings, while retaining their present height, were moulded into circular columns the same size all the way up, the male columns would be usually of greater cir- cumference than the female columns. As we found in Chapter III., there is only one measurement — the girth of the thighs — which is almost constantly larger in women. It is clear that we should be doing an injustice by comparing the amount of brain of the female column to that of the male column, for the male column must necessarily possess an absolutely larger amount of brain-tissue per foot, merely in order to equal the percentage amount of the female column. That additional ounce is fully needed merely to place men on a fair equality with women.
1 A discussion of this point will be found in Topinard's Anthropologic GSnirale, p. 557.
Google THE HEAD. 97 The evident inaccuracy of the stature criterion has therefore led a number of eminent craniologists — Clendinning, Tiedemann, Reid, Wagner, Weisbach, etc. — to adopt the method of estimating sexual differ- ences in brain-weight in accordance with their ratio to body-weight This is obviously a more logical method. The almost constant result is that, propor- tionately to body-weight, women are found to possess brains somewhat larger than men's, or else brains of about the same size. This was ascertained many years ago by Parchappe, Tiedemann, Thurnam, and others, in England, France, and Germany. 1 More recently Bischoff, in his important and accurate work on the brain, shows similarly that while woman's brain-weight is to man's as 90 to 100, woman's body- weight is to man's as only 83 to 100; Vierordt has also illustrated the same fact, that relatively to body- weight women have larger brains. 2 It may be taken as proved that in relation to body-weight — a more logical relation than that to body-height — women's brains are at least as large as men's, and are usually larger.
We have, however, not even yet reached a fair statement of the relative amount of brain-mass in men and women. To estimate brain-weight by its ratio to body-weight is satisfactory enough if we are dealing cautiously with very large averages. But it has to be remembered that we are comparing a comparatively stable element with one which is extremely unstable. The well-to-do, well-nourished, and comparatively lazy classes weigh much more than the under-fed and over-worked classes. The 1 See, for instance, Tiedemann, Phil. Trans. Royal Soc, 1836, vol. cxxvi., p. 306; Parchappe, Recherches sur V enciphale^ 1836, etc 2 T. L. W. von Bischoff, Das Hirngewicht des Menschen, Bonn, 1880; H. Vierordt, "Das Massenwachsthum der Korperorgane des Menschen," Archiv. filr Anat. u. Rhys., 1890; also tables in the same author's Anatomische Tabellen, 1892. Topinard [Anthrop. G£n.> pp. 530 et seq. ) does not find that there is much sexual difference either way.
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relations between body and brain may be quite different in the individuals who die in a workhouse from what they are in the ordinary population. There are not only differences between individual and individual; there are very marked fluctuations in the same individual A well-nourished individual dying after a slow and wasting disease has run its course, will appear to possess a relatively much larger brain than if he had died at the outset of the disease. Brain, although not the most stable tissue, is relatively stable, more stable even than bone; fat, which makes up a very large part of the general body-weight, is the most unstable tissue in the body; it is used up on the first call from the over-strained or under-fed organism; while, according to Voit's analyses, 97 per cent, of the fat has disappeared at the completion of starvation, the nervous system has only lost 3.2 per cent of its weight. 1 When we compare brain- weight with stature we are falling into a fallacy, but we are comparing elements that are at all events fairly constant, and therefore our error is fairly con- stant; when we compare brain-weight with body- weight we are on sounder ground, but one of our two elements fluctuates to a much greater extent than the other, and produces an error which is less constant and requires greater care to circumvent There is another serious and more constant error in estimating sexual differences in brain-mass by the ratio to the bulk of the body. Women, as we have already seen (p. 41), are fatter than men. There is a tendency in adult women to deposit fat about the breasts and arms, and especially in and around the abdomen, in the gluteal regions, and in the thighs, a tendency which only exists to a moderate extent in men. As we have seen, Bischoff found that the propor- tion of fat in the woman to that in the man was as 28.2 to 18.2, and that while the proportion of muscle to fat 1 See, for instance, in Waller's Physiology^ a diagram showing relative loss of different tissues under the influence of starvation.
Google THE HEAD. 99 in an adult man is as ioo to 43; in an adult woman it is as 100 to 78. Though his results were only founded on two typical well-nourished subjects, there is no doubt as to the general tendency of women to deposit fat It is part of what some have called the anabolic tendency of the female sex — the tendency to acquire rather than to expend — and it is further illustrated by the fact that while men attain their maximum weight at about the age of 40, women, whose growth terminates at a distinctly earlier period than that of men, do not attain their maximum weight until the age of about 50. Now fat is a comparatively non- vital tissue; it needs, compared to muscle, but very little innervation. Therefore it is not fair to women, in studying brain difference in relation to body- weight, to make no allowance for their excess of comparatively non-vital tissue. 1 Manouvrier estimates that the active organic mass of woman's body is to that of man's as at most 70 to 100. This is only an approximate estimate, but in any case the relative excess of brain-tissue in woman is very large, for the sexual ratio in brain-weight may be put with fair constancy, as we have seen, as 90 to 100.
The two usual and most convenient methods of estimating the sexual proportions of brain-mass — the ratio to body-height and the ratio to body-weight — are thus both erroneous, and in both cases the error leads to the assignment to women of an unfairly small mass of brain. It might be thought that there is some fallacy on the other side which would tend to restore the balance. Such a source of fallacy might be thought to lie in the massive bony skeleton of men, but this does not seem to be the case to any appreciable extent. If, for example, we take the 1 Professor Manouvrier, the well-known Parisian anthropologist, an energetic champion of the anatomical virtues of women generally, has especially drawn attention to this fact. (L. Manouvrier, Sur V Inter- pretation de la quantiti dans VEncephahy Paris, 1885; also Art. " Croissance" in Diet des sci. Anthrop, Google IOO MAN AND WOMAN.
skull, the average relation of the weight of man's to woman's is (if we accept Morselli's figures) as ioo to 86; the sexual ratio of weight of the large and well- to-do members of the Bath meeting of the British Asso- ciation was ioo to 79; of the small-sized Belgian race (according to Quetelet) it is ioo to 8?: so that while these two ratios of bulk differ widely (as we should expect), they oscillate around the sexual ratio of bone-mass. There is indeed one correction which must yet be made, and it is a correction which does something towards restoring relative predominance of brain tissue to men. Independently of sex, and (at all events among Mammalia) independently even of species, increase of body-size has a fairly constant and regular tendency to be accompanied by an in- crease of brain which is relatively less in amount Tall men have smaller brains, relatively, than short men; tall women have, relatively, smaller brains than short women; and the shortest women have brains that are relatively much larger than those of the tallest men. 1 This law involves a correction which is not large, being scarcely two per cent, and perhaps even less, for Bischoff and Tigges have shown that brain increases with height to a greater extent in women than in men. This consideration, however, serves to complicate the problem of the brain-ratio, and to reduce somewhat the estimate of the relative predom- inance of brain tissue in women. No satisfactory plan has yet been devised for avoiding the fallacies involved in measuring the brain by the ratios to stature and bulk. The relation of the brain to a bone (such as the femur), or to the heart or to some particular muscle, are among the methods that have been suggested. Possibly a fair approximation to a 1 Bischoff, Broca, Topinard, etc., have shown that this holds good for either the stature-ratio, the bulk-ratio, or both. See, for example, Bischoff, Das Hitngewichty p. 32; Topinard, Anthrop. Gen., p. 533; J. Marshall, " On the Relation between the Brain and the Stature and Mass of the \$o&y"JounalofAiiat. and Phys.^ July 1892.
Google THE HEAD. 101 correct ratio might be obtained by accepting the ratio to bulk and making a plus or minus correction founded on, for example, the deviation from a certain definite standard of the relation of thigh-girth to knee-girth. There is ample scope here in the future for the efforts of the mathematical anthropometrist It is sufficient at present if we are generally agreed as to the nature and directions of the errors in the usual methods.
There is, therefore, no doubt that when we have eliminated the chief disturbing errors, we are com- pelled to conclude that women possess a relatively larger mass of nervous tissue than men. This by no means necessarily implies that women have any natural advantage over men. The fact that the absolutely large brain is to a great extent the appanage of a large muscular system apparently contributes to its steadi- ness and tone. A relatively large brain not rooted in a good muscular foundation is not always a good gift of the gods; it is often difficult to turn on effectively to intellectual tasks; it acts uncontrollably and with too much facility; it may be liable to explosive out- bursts; it is a fact of some significance that the epileptic possess relatively large brains. 1 A very con- siderable proportion of the good work of the world has been done by brains which were large, though, relatively to the bulk of the body, not inordinately large.
There is nc doubt that some men of genius, in the departments both of science and of art, have possessed brains that were enormously large, both absolutely and relatively. But it is not doubtful that a brain both absolutely and relatively large is a possession of most uncertain value. Taking the six largest recorded male brains (without special research but eliminat- ing those of dubious authenticity), we find one (guaranteed by Bischoff) as large as 2222 grs., which 1 See, for instance, Clapham, Art "Brain, Weight of," Diet. Psych, Med.
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