Beyond the forementioned characteristics, the task of race recognition from observation of the skull is one of great difficulty and perplexity with illusory results. A considerable experience of several years with the large collection of skulls in the Army Medical Museum enables me to speak advisedly on this point.[573]
Although the technical procedures of craniometry require special measurements and employ an arsenal of special instruments, the results are far from conclusive as regards the determination of human types. Time and space do not permit the mention even in epitome of the various methods most relied upon by trained craniologists. Among the oldest operations of cephalometry, as well as the most incomplete, is the measurement of the so-called facial angle, which is employed to distinguish the skull of a lower order of animal from that of the negro and the white man. This angle, acute in the skulls of the lower animals, approaches a right angle as we ascend the zoological scale; being from 30° to 65° in the various apes; 75° in the Mongolian; about 70° in the negro, and between 80° and 90° for whites. The prognathous (projecting) jaws of the negro cranium are distinctive, as well as the shape of the nasal opening, which in the black is an equilateral triangle, while it is isosceles in the white. The books usually speak of the Eskimo skull as pyramidal, which in point of fact is not true. Inspection and examination of a large collection of Eskimo crania has changed and greatly modified some of the previous notions of the conventional Eskimo skull. From more than one hundred, collected in the vicinity of Bering Strait,[574] I find that the skulls present very considerable variations among themselves; some being brachycephalic, others dolichocephalic. In many the facial angle is 80°, and in one instance 84°, which exceeds that observed by me in many German skulls. Nor is the prominence of the zygomatic arches such a constant difference in the configuration as to justify one in speaking of the skull as pyramidal. On the contrary, in many of the specimens lines drawn from the most projecting part of the zygomatic arch and touching the sides of the frontal bone, instead of forming a triangle on being elongated, might, like the asymptotes of a parabola, be extended to infinity and never meet. The index of the foramen magnum in these skulls is about the same as that of European crania. The internal capacity shows marked difference, the cubic contents of the endocranium averaging that of the French or Germans.
As some modern writers lay great stress on the measurement of the cranial capacity, not only as an aid to race identification, but as an adjunct in the study of the criminal and insane classes, it may not be amiss to give the salient facts relative thereto.
It is admitted that the cranial capacity may vary with the intellectual state, hydrocephalic skulls, of course, being excluded. Microcephalic adults give a figure inferior to that of gorillas, some being as low as 419 c.c. Andaman Islanders and autochthonous Australians appear, in respect to cranial capacity, to be most badly off. The capacity of an Andaman has been found as low as 1,094 c.c.; while that of Australians (autochthonous) and of some American tribes show an average capacity of 1,224 c.c. in the normal as well as in their deformed crania. The cranial capacity increases in the yellow races and attains its maximum in the white races. In the middle European race 1,500 c.c. may be accepted as the average; 1,750 c.c. is the maximum, and anything above is macrocephalic; while the minimum is 1,206 c.c., which is rather too low than too high. According to Topinard’s nomenclature of the cranial capacity, macrocephalic in the adult European male are those having a capacity of 1,950 c.c. and above; a large skull is one of 1,950 to 1,650 c.c.; average or ordinary, 1,650 to 1,450 c.c.; small, 1,450 to 1,150 c.c.; microcephalic 1,150 c.c. and below. It would seem that the skulls of the insane are below the type, a measurement of sixteen male skulls giving an average of only 1,449 c.c. Scotchmen head the list with the most voluminous skulls, and according to a tabular statement made up from Welcker, Aitken, Broca, and Meigs, the English come next, with a capacity of 1,572 c.c. Then follow Eskimo, 1,483 c.c.; Germans, 1,448 c.c.; French, 1,403 to 1,461 c.c.; South African negroes, 1,372 c.c.; Ancient Peruvians, 1,361 c.c.; Malay, 1,328 c.c.; Mexican, 1,290 c.c.; Hottentot and Polynesian, each 1,230 c.c.; Australians, 1,364 c.c.; and Nubians, 1,313 c.c. The cranial capacity in man, like that of the anthropoid apes, varies according to sex, the difference being so great that it is necessary to measure separately.
In the troglodyte skulls of prehistoric times the variation is not more than 99.5 c.c.; but in the contemporaneous races the difference varies from 143 to 220 c.c. French craniologists usually speak of the Auvernats as possessing the highest cerebral capacity (1,523 c.c.), and mention the skull of a Parisian of 1,900 c.c. as the highest known. Some Eskimo skulls, however, measure from 1,650 to 1,715 c.c., and two eurycephalic Indian skulls in the anatomical section of the Army Medical Museum measure respectively 1,785 and 1,920 c.c.
Mr. Havelock Ellis, speaking of the psychic characteristics of criminals, says that the lower human races present a far larger proportion of anatomical abnormities than the ordinary European population; and Sir William Turner writes of the skulls collected during the Challenger expedition that although their number is certainly too limited to base any broad generalization on, as to the relative frequency of occurrence of particular variations in the different races, there is obviously a larger proportion of important variations than would occur in a corresponding number of skulls of the white races. Thus, for example, the squamo-frontal articulation is found in less than two per cent of European skulls, while it is found in twenty per cent of negroes, according to Ecker, and 16.9 in Australian skulls, according to Virchow. Again, the spheno-pterygoid foramen is found in 4.8 per cent of European skulls and in 20 per cent of American Indians; 30 per cent in Africans; 32 per cent in Asiatics, and 50 per cent in Australians. The wormian bones are also more common among the lower races; as a rule, the cranial sutures coalesce much earlier and the teeth are more precocious.
Photography, though of undoubted service in craniometry, has been applied as a crucial test in the matter of identity and found wanting. It is objected to on the ground that it has no character of precision, and that photographs of the skull have the common defect of being central, not orthogonal projections, such as anthropometry requires. Besides, the lenses of cameras are not uniformly perfect. Anatomists know, moreover, that salient differences in any collection of crania prevent methodical enumeration and constitute the stumbling-block of ethnic craniology. Cephalometry shows, further, that dolichocephalic, mesaticephalic, and brachycephalic skulls do not belong exclusively to the white, the yellow, or the black race, but exist among the three as a result of evolution.
On this subject Professor Lombroso, among the foremost contemporaneous medico-legal writers, cites the cranial asymmetry of Pericles, of Romagnosi, of Bichat, of Kant, of Chenevix, and of Dante, who presented an abnormal development of the left parietal bone and two osteomata on the frontal bone. Besides, there is the Neanderthaloid skull of Robert Bruce and the ultra-dolichocephaly noticeable in the skull of O’Connell, which contrasts with the mesocephaly of the Irish. The median occipital fossa is noticeable in the skull of Scarpa, while Volta’s skull shows several characteristics which anthropologists consider to belong to the lower races, such as prominence of the styloid apophyses, simplicity of the coronal suture, traces of the median frontal suture, obtuse facial angle (73°), and moreover the remarkable cranial sclerosis, which at places attains a thickness of 16 mm. (five-eighths of an inch). Further mention is made of the submicrocephaly in Descartes, Tissot, Hoffman, Schumann, and others.
De Quatrefages noted the greatest degree of macrocephaly in a lunatic, the next in a man of genius. Cranial capacity in men of genius is usually above the average, having been found as high as 1,660 c.c. in Thackeray, 1,830 c.c. in Cuvier, and 2,012 c.c. in Tourgueneff. The capacity is often found above the average in insanity, but numerous exceptions occur in which it drops below the ordinary average, as in the submicrocephalic skulls of Liebig, Döllinger, Hausmann, Gambetta, Dante, and Shelley.
From what has just been said, it follows that skull measurements for medico-legal purposes have no more significance than the fact that some men are taller and some shorter than others. The medical jurist should, therefore, not be too dogmatic in drawing conclusions as to race from the skull alone. To complete the diagnosis in the matter of skeletal race peculiarity, the splay foot of the negro with the unusual backward projection of the heel-bone, as well as the greater relative length of the tibia and of the radius, may be taken into consideration. There are other characteristics of the lower jaw and of the facial bones generally, the study of which leads up to the realm of transcendental anatomy; so their further consideration would hardly appeal to the “dispassionate, sympathetic, contemplative jury” of our enlightened countrymen.