The different internal or external organs of man afford also some special characters, though not very numerous, for differentiating race.
The muscular system, little known outside white races, has, up to the present, not given any important indication on this point. At the very outside, we can say, thanks to the works of Chudzinsky, Le Double, Macalister, Popovsky, Testut, Turner, etc., and the Committee of the Anatomical Society of Great Britain and Ireland, that certain muscular anomalies are more frequent in the Negro than in the White, and that the muscles of the face are less differentiated in the former than in the latter.[97] In the splanchnic system some differences have also been observed between the White and the Negro, notably the excessive volume of the liver, the spleen, the suprarenal-capsules, and, in general, the hypertrophy of all the organs of excretion in the latter compared with the former. The venous system appears also to be more developed in the Negro than in the White. Somewhat notable differences must certainly be observable in the structure and general conformation of the organs of the voice and of speech—tongue, larynx, lungs. But our knowledge on this subject is still very imperfect. Attention has been drawn to the feeble development of the anterior fibres of the stylo-glossal muscle of the tongue, the greater development of the Wrisberg cartilage of the larynx with the muscles stronger in the Negro than in the White,[98] but nothing is known about the larynx of other races.
There is nothing, even to the bony parts of the vocal apparatus, which does not undergo ethnic variations. Thus the larger cornua of the hyoid bone are not attached to the body of it in 75 to 95 per cent. of cases observed among the Indians of America, whilst the same anomaly is met with in only 25 to 35 per cent. of cases among Europeans, and only in 30 per cent. among Negroes, which probably harmonises with the differences in the production of sounds in the language of each of these peoples.[99]
The genital organs also present some differences according to race, but rather in the dimensions of the various parts than in their form. The only peculiarity worth notice is the exaggerated development of the labia minora among the Bushman women, known under the name of “apron.” This peculiarity, which appears from infancy, is met with only among the Bushman race and the people into whose composition enters the Bushman element—Hottentots, Nama, Griqua, etc.[100]
The breasts of women may also present variations of form. Ploss[101] classes them under four heads according to their height, which is inferior, equal, or more or less superior to the diameter of their base; we have thus mammæ like a bowl or the segment of a globe, hemispherical, conical, and pyriform. These forms may be found in combination with a more or less extended and prominent areola, and with a nipple which may be discoidal, hemispherical, digitiform, etc. It is especially among Negresses that we meet with conical and pyriform mammæ, and digitiform nipples, while mammæ shaped like the segment of a sphere predominate among Mongolian and European women of the fair race; women of the south-east of Europe and hither Asia have for the most part hemispherical breasts.
Among the internal organs, the brain, or better, the encephalon, deserves a little more attention. I have already said with regard to cranial capacity (p. [56]) that appreciable differences have been observed in the volume of the brain-case according to age, sex, and race. This difference is in harmony with irregularity in the volume and consequently in the weight of the brain. At birth, European boys have 334 grammes of brain on an average, girls 287 grammes. This quantity increases rapidly up to 20 years of age, remains almost stationary between 20 and 40 or 45, then begins to decrease, slowly at first, until 60 years, then more rapidly.
Let me also add that the weight of the encephalon varies enormously according to individuals. Topinard[102] in a series of 519 Europeans, men of the lower and middle classes, found that variations in weight extended from 1025 grammes to 1675 grammes. The average weight of the brain among adult Europeans (20 to 60 years) has been fixed by Topinard, from an examination of 11,000 specimens weighed, at 1361 grammes for man, 1290 grammes for woman. It has been asserted that the other races have a lighter brain, but the fact has not been established by a sufficient number of examples. In reality all that can be put against the 11,000 brain-weighings mentioned above concerning the cerebral weights of non-European races, amounts to nothing, or almost nothing. The fullest series that Topinard[103] has succeeded in making, that of Negroes, comprises only 190 brains; that of Annamese, which comes immediately after, contains only 18 brains. And what do the figures of these series teach us? The first series, dealing with Negroes, gives a mean weight not much different from that of Europeans—1316 grammes for adult males of from 20 to 60 years; and the second, dealing with the Annamese, a mean weight of 1341 grammes, almost identical with that of Europeans. For other populations we have only the weight of isolated brains, or of series of three, four, or at most eleven specimens, absolutely insufficient for any conclusions whatever to be drawn, seeing that individual variations are as great in exotic races as among Europeans, to judge by Negroes (1013 to 1587 grammes) and by Annamese (from 1145 to 1450 grammes). Even in the great series of Europeans, surprises await us in comparing the figures. Thus Peacock found an average of 1388 grammes for the English from a series of 28 brains, whilst Boyd finds 1354 grammes from a series of 425 brains. The difference (34 grammes) is greater here than between the brains of Annamese and Europeans, and hardly less than that which we have just found between Negroes and Europeans (45 grammes). For the French the figures are more in agreement. Broca found from the weights of 167 brains an average of 1359 grammes, and Bischoff[104] from 50 brains an average of 1381 grammes; difference, 22 grammes.
Not having at our disposal sufficient data for the weight, let us see if the cranial capacity could not supply them, for we know, since the investigations of Manouvrier,[105] that we have just to multiply by the co-efficient 0.87 the capacity of the cranial cavity to get with reasonable exactitude the weight of the brain which it contained. This is what we learn from the figures of cranial capacity brought together by Topinard,[106] after the necessary corrections, and reduction to cubic measurement by the system of Broca: among Europeans the measurement is 1565 c.c. on an average for men, varying from 1530 c.c. (22 Dutch) to 1601 c.c. (43 Finns). We have in various series the following succession of cranial capacities for the populations of the other parts of the world: the greatest is contained in a series of 26 Eskimo (1583 c.c.), the least that of 36 Australians (1349 c.c.) and of 11 Andamanese (1310 c.c.). Between these two extremes the other populations would be thus arranged in a decreasing order of capacity: 36 Polynesians (1525 c.c.), 18 Javanese (1500 c.c.), 32 Mongols (1504 c.c.), 23 Melanesians (1460 c.c.), 74 Negroes (1441 c.c.), and 17 Dravidians of Southern India (1353 c.c.).
The difference between the highest and lowest of these figures is 255 c.c., a little greater than that which is shown between man and woman in all races. On the other hand, Manouvrier[107] gives the following weights, deduced from cranial capacities: 187 modern Parisians, 1357 grammes; 61 Basques, 1360 grammes; 31 Negroes, 1238 grammes; 23 New Caledonians, 1270 grammes; 110 Polynesians, 1380 grammes; and 50 Bengalis, 1184 grammes; the difference of the two extremes is 196 grammes. Must we then see in these differences the influence of stature and bulk of body, as appears unquestionable in the sexual difference? We are tempted to believe it when we see that the mean weight of the largest brain in Europe has been found among the Scotch (1417 grammes, an average obtained by Reid and Peacock from 157 brains), whose stature is the highest of the human family, and that the mean weight of the Italians, whose average stature is rather small, is only 1308 grammes (from 244 cases weighed by Calori). The Polynesians and the Caucasians,[108] peoples of high stature, also outweigh the Andamanese and the Javanese, of very low stature. However, we see (from weights and cranial capacity) that Negro populations of very high stature, also Australians and New Caledonians of medium stature, have the cerebral weight much smaller than the Eskimo and certain Asiatics of low stature, like the Javanese.