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of the brain to the functions of the intellectual powers, the conjecture is still permissible that the higher psychical functions may be connected with an externally insignificant accretion of the brain.
Again, it is usually held that unimpaired intellectual faculties exist in man only when the weight of brain exceeds a minimum limit which varies according to sex and race. Quatrefages wanted to fix the weight of brain in Europeans at 1113 grams for males, and 977 grams for females. Carl Vogt assumes only 1000 grams in the first case, and 900 grams in the second; while H. von Luschka pronounced 1000 grams to be the minimum weight of a brain of unimpaired efficiency.9 Weighed in a fresh condition, he found the brain of a microcephalic woman only 30, and of a man even 20 Loth, 10 or about 10 oz. With the exception of the elongated form of the brain-case, and a great projection of the jaws, there is nothing of an animal character in the skull of these unhappy beings, for Virchow has decisively contradicted Carl Vogt's assertion that the position of the occipital foramen is abnormal. The same observation applies to the conditions of the basisphenoid bone, which of course ought to be compared in adult microcephali and adult apes of a high order, not between adult microcephali and young apes. " Carl Vogt had ventured to compare the skulls of these abortive human beings with the skulls of apes. According to his tables the capacity of the brain-case amounted to 622 cubic centimetres in one idiot, to 460 in another; while that of a male gorilla reached 500 cubic centimetres. 12 Relying on these researches, he supposed himself to have perceived in these human malformations a reversion or, in the language of the Darwinian theory, an atavism, which, by the reappearance of ancestral characters of remote times, affords testimony of the animal
* Rapport sur les progrès de l'Anthropologie, p. 324.
8 Vorlesungen über den Menschen, vol. i. p. 103.
9 Dritte Versammlung der Deutschen Gesellsch., p. 17.
10 At the time this was written 32 Loth = 1 German lb. = 11023 English Ib., but by the new regulations there are but 30 Loth in the German lb.
11 Menschen und Affenschädel, p. 31.
12 Mémoires sur les Microcéphales, in the Mém. de l'Institut National Genevois, vol. ix. p. 54.
derivation of our forefathers. But at the third meeting of the German Anthropological Society, all the specialists remonstrated against this interpretation of the facts. With almost an identity of expression the microcephali were recognized as human creatures which, by reason of morbid arrest of development, were rendered incapable of development, and in no way as intermediate links filling the chasm which separates man from the creatures most resembling him in the animal world. That reproductive powers are wanting in idiots, is enough to prove that the ancestors of man never occupied a microcephalous grade-that no part of the world was in past ages peopled with Crétins. 13
The human brain must therefore be compared only with other human brains. This is approximately accomplished by measuring the capacity of crania of various races of mankind. Water is not generally used, because it necessitates the closing of the numerous apertures in the bones. Lime or plaster of Paris can be used only after transverse sections have been made, that is to say, only in damaged skulls, and afford no really comparable results, as these materials have different specific weights; these substances have therefore been abandoned, even by those who previously recommended them.14 The brain capsule is now filled either with millet seed or small shot, and the contents are then poured into a metrical gauge. Sand is sometimes used, but with very unreliable results. Wyman, in the fourth volume of the Anthropological Record, states that the capacity of one skull, which was measured with sand eight times, appeared to vary between 1290 and 1350 cubic millimetres; when measured with shot the variation was only between 1200 and 1205. By these means we ascertain the capacity of the brain-capsule in different races. Lucae's measurements tend to show that the broadest negro skull does not reach the average of the Germans, nor the best Australian skull the average of the negro, and also that the individual fluctu
18 Comp. the speeches of Von Luschka, Virchow, Ecker, Schaaffhausen, and Jäger, in the account of the third meeting of the German Anthropological Society, pp. 16-25; and also H. Schüle, in the Archiv für Anthropologie, vol. v. p. 444-446. 1872.
14 Lucae, Morphologie der Racenschädel, § ii. p. 45. 1864.
Weight of Brain in Various Races.
ations increase with the rise of the numbers.15 Broca's results seem to confirm these. Assuming 100 as the average capacity of the Australian skull, he estimates that of the negro at 1116, and of the Teuton at 124.8.16 The suspiciously high averages at which Barnard Davis arrived, based on the richest of all collections, do not seem so unfavourable to those human races which we regard as low." He found the capacity of the cranium to be in
Number of Skulls.
In addition to these averages derived from numerous individual estimates, it is advisable to glance at the fluctuations. Thus Morton, among skulls of all races, found one minimum specimen of 63 cubic inches, and one maximum of 114 internal capacity.18 But Barnard Davis has in his possession an ancient Roman skull of only 62 cubic inches, and an Irish specimen of 121.6. Another Irish skull in the Bateman Museum even reaches 1242 cubic inches. 19 Even within the same family of nations the greatest differences may occur, for some Tuscan skulls are far behind the
15 Lucae, Morphologie der Racenschädel, § ii. p. 45. 1854. (These capacities were taken with millet seed).
16 Broca, cited by Quatrefages, Rapport, p. 306.
17 Thesaurus Craniorum, p. 360.
18 Huxley, Man's Place in Nature, p. 77.
19 Thesaurus Craniorum, pp. 65 and 360.
narrowest Australian specimens in point of internal capacity. In a Florentine servant maid, 23 years of age, Paolo Mantegazza found only 1046 cubic centimetres, but in an adult Florentine man 1727 cubic centimetres, and in a supposed Etruscan warrior even 1750 cubic centimetres. 20
If the smaller average capacity of the cranium is causally connected with arrested intellectual development, we might expect that the skulls of ancient Europeans would be of smaller size than those of their descendants: many facts point this way. Broca thinks that he has found an increasing capacity in the crania of modern Parisians (1482-1484 cubic centimetres) contrasted with those of the 12th century (1426 cubic centimetres). Skulls of ancient Greeks recently exhumed at Athens, especially those of a wealthy lady of the Macedonian period, Glykera by name, with only 1150 cubic centimetres, and of a man 1280 cubic centimetres, both favour this opinion.22 On the other hand, His and Rütimeyer have given, as an average for their Disentis type, to which belong three-fourths of the modern Swiss, 1377 cubic centimetres; for the Hohberg type, nominally ancient Romans, 1437 cubic centimetres, and for the Sion head, which corresponds with the skulls of the lake dwellings, 1558 cubic centimetres min. 1450). According to this computation the Swiss population
must have lost considerably in cranial capacity ;23 but as this is hardly credible, the fact ought to serve as a warning against measurements of skulls taken from graves.
The investigation of these dimensions is obviously a means of inferring, at least approximatively, the size of the brain. On the weight of this organ we for a long time possessed only an introductory work by Rudolf Wagner. Unfortunately, the majority of the 964 skulls examined were derived from individuals of unsound mind, and ought therefore to have been excluded from
20 Archivio per l'antropologia, vol. i. p. 53 et seq. Firenze, 1871.
21 Broca as cited by Carl Vogt, Vorlesungen über den Menschen, vol. i. pp. 105-108.
22 See Virchow's account in the Verhandlungen der Berliner anthropol. Gesellschaft, p. 174 et seq. 1811.
23 Crania Helvetica, p. 44. Basle, 1864.
Size of the Brain.
the comparison. Again, the estimates of weight were taken from various anatomists, who do not appear to have adopted the same method of procedure. It was also to be regretted that the bodily dimensions of the corpses examined were only occasionally stated. As a weight of 1861 grams was found in Cuvier, and in Lord Byron (though this is founded on equivocal statements) 1807 grams, a high weight seemed to be accompanied by high intellectual endowments. Yet among eminent scholars of Göttingen, such as Dirichlet (1520 gr.), the great Gauss (1492 gr.), the pathologist Fuchs (1499 gr.), the philologist Hermann (1386 gr.), and the mineralogist Haussmann (1225 gr.), the weights sank to the general average, and even far below it. 24 As the only permanent result of this first attempt, it may be noticed that Wagner found the average weight of the female brain to be lighter than that of the male. This fact was strictly corroborated by Weisbach as regards the German and Sclavonian populations of Austria. Calori, moreover, relying on a large number of estimates of weight, taken from Italian specimens, has found that the female brain is lighter by 150-200 grams. The capacity of the skull is likewise different in the two sexes according to the following statistics arranged by Weisbach.25
CAPACITY OF THE FEMALE AS COMPARED WITH THE MALE CRANIUM, THE LATTER = 1000.
24 Rudolf Wagner, Die Wendungen der Hemisphären u. das Hirngewicht, Göttingen, pp. 32, 33. 1860. In his published letter to Barnard Davis “on the skull of Dante," Welcker has, however, proved from the estimates given by Wagner and others, that the brains of 26 men of high intellectual rank collectively surpass the average weight of brain by 14 per cent. Dante's brain (1420 gr.) is nevertheless but little above the average of 1360 grams.
25 Der Deutsche Weiberschädel. Archiv für Anthropologie, vol. iii. p. 63.