I.Osteological characters.—Without denying the very great value of external characters, I agree with almost all anthropologists, in attaching a greater importance to anatomical charactersin the majority of cases. Unfortunately, the comparative anatomy of human races has, as yet, made but little progress. The fact is, that the solid portions, the skeleton alone, have, necessarily, been the subject of serious examination. The study of the perishable portion has scarcely been begun. For this, and several other reasons, I shall distinguish these two orders of facts, and discuss separately our knowledge ofosteological charactersandorganic characters.
The skeleton, the framework of the body, presents the same regions as the latter: we can distinguish the head, the trunk, and the extremities. Each of these regions offers peculiarities more or less connected with the diversity of human groups. The best studied, and fortunately the most important, are furnished by the head. For some years craniological collections have been singularly on the increase; and throughout Europe, the study has been entered upon with equal ardour. Craniometrical methods and instruments have multiplied, perhaps a little beyond the actual need. MM. Vogt and Topinard have made an excellent summary of this mass of research. I can only refer to their publications. I cannot here even reproduce all the results already acquired, and must confine myself to pointing out a few of the principal ones.
II.Characters drawn from the cranium alone.—From an anthropological point of view, as well as in an anatomical sense, the skull is divided into two parts, thecraniumand theface. Each of these regions has its special indications, while new characters again rise from their reciprocal relations. Let us briefly review them.
The general form of the cranium depends, above all, upon the relation existing between thelengthmeasured from before backwards, and thebreadthtaken from one side to the other. The honour of having appreciated the importance of this relation belongs to Retzius. He made use of it to establish the distinction betweendolichocephalic, or long-headed races, andbrachycephalic, or short-headed races.
Retzius considered the relations 7 : 9 or 8 : 10 as representing the limit, left by him uncertain, of dolichocephaly and brachycephaly. M. Broca proposed the formation of a third group, which should comprise all crania, the length and breadth of which presented a relation comprised within these limits, and anthropologists now admit with him themesaticephalicraces. In expressing these relations by decimals, and in creating the termhorizontal cephalic index, now universally adopted, M. Broca has, moreover, facilitated, to an extraordinary degree, the study of this character, and the ideas to which it may give birth. His sub-division of the two extreme groups into two has also, in certain cases, been an advantage. He has himself, however, shown that it is not wise to go too far in this direction.
The definitions of dolichocephaly, mesaticephaly, and brachycephaly have, it seems to me, been somewhat arbitrary. I draw this conclusion from the following tables, which I borrow from MM. Broca and Pruner Bey. They represent the means discovered by these eminent investigators. I have merely substituted the serial order for the purely geographical distribution adopted by M. Pruner. Moreover, I have continued the calculation to the second decimal place, thus rendering the distinctions more minute, and the general result more striking.
INDICES OF HUMAN RACES AFTER M. PRUNER BEY.
INDICES OF HUMAN RACES AFTER M. BROCA.
These tables mutually confirm and complete each other in general results. The secondary differences which distinguish them, are doubtless occasioned, on the one hand, by the number of crania employed by the two authors to obtain their means; on the other, from some diversity in the use of these materials. M. Pruner Bey distinguished the sexes, which are united by M. Broca: the latter has placed in one group the Hottentots and Bosjesmans, separated by M. Pruner, etc.
From M. Broca’s table it appears that the mean of all these indices, leaving deformed skulls out of the question, is 0·78. From a numerical point of view this would be that of true mesaticephaly. The mean group ought, it seems to me, to descend equally as it rises, and consequently to absorb at least a part of M. Broca’s sub-dolichocephali. In fact, upon inspecting the two tables, it appears that the indices above 0·74 and below 0·79 comprise the greater number of races belonging to the three fundamental types, and taken from allparts of the world. It seems to me that true mesaticephaly should be comprised within these limits. I do not, however, propose that those which have been adopted should be changed.
These tables give rise to many other observations, of which I shall only point out the principal.
M. Pruner Bey carried his calculations to the third place of decimals; M. Broca to the fourth. I have gone no further than the second, that the eye may be more easily attracted by the series formed by these numbers, so important in the characterization of races. It should be remembered that the greater number are means taken from a certain number of crania. Were there a sufficient number of subjects for each race, and all the indices taken from each arranged in serial order, the distance from one to the other would undoubtedly be no longer 0·01, but would be diminished to 0·001, or even less. The insensible shades observed in passing from one individual to another would here be as remarkable as in the comparison of stature.
There is no need to insist at any length upon the intercrossing, so strikingly betrayed by the two tables. We see that the same index places side by side the most dissimilar races, the South German with the Annamite, the Breton with the Kalmuck, the Belgian with the Tagal, the Parisian with the Malay, the Italian with the Maori, etc., and that by their several indices the white races are scattered throughout almost all the coloured races. I need not return to the consequences which may be drawn from these facts from a monogenistic point of view.
The yellow and black races are not so widely separated as the white; the former are either brachycephalic or mesaticephalic, the latter all dolichocephalic, with the exception of the Aëtas. I have shown that the latter belong to a group of populations extending from the Andaman and Philippine Islands to Torres Strait in Melanesia, penetrating New Guinea, and forming a specialbranchin the midst of the Melanesian Negro population.
The case appears to be somewhat similar in Africa. This discovery, entirely contrary to the ideas generally maintained till the present time, is due to M. Hamy. This excellent investigator recognized brachycephaly in six skulls taken from the Paris collections, and obtained from Cape Lopez, or the mouths of the Fernand Yaz. Shortly afterwards, M. Duchaillu having brought from the same districts ninety-three skulls, the measurements of which were made public by Englishmen, M. Hamy calculated the indices, and found that twenty-seven of these crania were brachycephalic or mesaticephalic. There is then every indication that the Negrostockin Africa presents a specialbranchcorresponding to the Negritoes. This result is confirmed by Schweinfurth, who places the Niams-Niams and some neighbouring tribes amongst the brachycephali.
We see that the horizontal cephalic index cannot serve as a starting point in the classification of human races, as Retzius imagined it might. We also see, however, that all the value which was attributed to it by its author, is preserved in the characterization of secondary groups.
The extreme means given in M. Pruner Bey’s table were found in two American races, the Esquimaux and the inhabitants of the Pampas of Bogota, etc. Whatever the differences may be which separate these two races, it is evident that neither of them belong either to the black or the white type. They show the greatest affinity to the yellow type.
From one extreme mean to the other there is, according to M. Pruner, a difference of 0·246 between the cephalic indices; according to M. Broca of 0·14552 only. This difference rests chiefly upon the fact of M. Broca rejecting, as deformed, skulls which M. Pruner seems to accept without observation. Again, the individual indices present a much wider variation than would, at first sight, be expected. Huxley mentions a Mongol whose cephalic index rises to 0·977, and a New Zealander, of unmistakable Melanesian origin, in whom it descends to 0·629. The difference is, therefore, 0·348.
The general relations of length and breadth in the cranium of human races is apparent from birth. Nevertheless, from the researches of Gratiolet, it appears that dolichocephaly is due to a relative development of bones, which varies with age. In the infant it is essentiallyoccipital, in the childtemporal, andfrontalin the adult man. In the woman the elongation of the cranium depends essentially on the length of the temporal regions; in this respect, then, the woman remains a child all her life.
Starting from these primary results, the same observer has compared dolichocephalic Whites with African and Melanesian Negroes. He found that the frontal dolichocephaly of the former was replaced in the two black races by an occipital dolichocephaly. M. Broca has established the same fact in comparing Basques with Parisians. Thus the distinction proposed by M. Gratiolet furnishes a secondary character, which may be of use in certain cases, but which falls very short of the importance with which some have attempted to invest it. They would consider occipital dolichocephaly as a character which widely separates the Negro from the White; the observations of M. Broca show that this is not at all the case, and from the observations of M. Gratiolet it appears that we have here only the persistence of an anterior condition common to both. The Negro and the Basque preserve throughout life the cephalic character of the infant Parisian, thus forming one of the many examples of that cessation of evolution which, as we see more distinctly every day, plays a considerable part in the characterization of human races.
The study of the horizontal cephalic index might lead to many other remarks. I shall only recall the results obtained by M. Diétrici. It appears from his calculations that, the total population of the globe given at 1288 millions, there are 1026 millions of dolichocephali, and only 262 millions of brachycephali. But the Berlin savant places in the first category the Chinese, who are mesaticephali, and must alone be reckoned at 421 millions. All these facts considered, itappears to me, from the tables of MM. Pruner Bey and Broca, and other data, received up to the present time, that the mesaticephali are much more numerous than either the brachycephali or dolichocephali. If mesaticephaly is taken in the sense pointed out above, the latter in their turn predominate over the brachycephali, owing chiefly to African black populations, which we are daily learning to estimate as much more dense than they were formerly thought to be.
Retzius only compared the antero-posterior and transverse maximum diameters. Later investigators have sought the relation between the latter and the height of the cranium. Thevertical cephalic indexhas thus been obtained, the importance of which is at once evident. It plays an equally important part in the table of M. Pruner Bey, and gives rise to considerations analogous to those just discussed. I cannot, however, enter into all these details without exceeding the limits of this book. From the same motive I shall not mention the other measurements of the cranium, maximum and minimumfrontal diameters,total circumference,antero-posterior arc, and others.
The composition of the cranium can only vary within very narrow limits. Nevertheless, in Negroes, in ancient Egyptians, etc., the squamous portion of the temporal bone is sometimes united to the frontal without the partial interposition of the wings of the sphenoid. This is a remarkable fact, being in direct contradiction to theprinciples of connections, so justly regarded by Etienne Geoffroy as one of the most essential principles of comparative anatomy.
In the preceding case, the composition of the cranium is altered by the suppression of a normal suture. This may also be caused by the appearance of an abnormal suture, by which two distinct bones are formed from a single one. Such is the case when the occipital bone seems to divide, so as to leave its upper portion free. We then have what has been called theepactal bone, orbone of the Incas, because Rivers and Tschudy imagined this conformation to be a character peculiarto the race. M. Jacquart, however, showed that it was merely the result of a cessation in the evolution of the occipital bone, of which examples are found in the most different human races. It is to a similar phenomenon that the persistence of the medio-frontal suture is due. This, again, is doubtless universal, but much more frequent in the Aryan white race than in coloured races, and especially in the Negroes.
These facts are connected, moreover, with a group of observations and ideas which Gratiolet has brought forward on several occasions. According to this ingenious observer, the anterior sutures are the first to unite in inferior races, while in superior races the obliteration commences with the posterior sutures. Again, the sutures, as a whole, have a tendency to disappear rapidly in savage races, while the isolation of the bones of the cranium is persistent in civilized races, and particularly in the European White. This disposition allows a continuance of the development of the brain, although it gradually becomes slower. Gratiolet thus explains the continuance of the intellectual power, so remarkable in men who have constantly exercised their intelligence. The statistic researches of Dr. Pomerol, while correcting all that is absolute in this theory, seems to confirm it in some respects.
Since I am unable to review all the cranial characters, I shall pass by those drawn from the prominence of different bones, the occipital indices of Broca, the cephalo-spinal of Mantegazza, etc. I shall only say a few words upon the position of the foramen magnum, and the sphenoïdal angle of Welker, but I shall dwell more at length upon thecapacityof the cranium.
D’Aubenton, in a special work, shows that the foramen magnum is always placed further back in animals than in man. Sœmmering remarked that it seemed more so in the Negro than in the White; and this opinion, which was apparently confirmed by some measurements, was at once accepted by a number of anthropologists, and regarded by themas asimian character, but this result was attained by considering the position of the aperture relatively to the entire length of the skull, including the face. Now it is at once evident that the forward development of the latter, by reason of prognathism, would increase the apparent retreat of the former.
The researches of M. Broca uponcranial projectionsenable us to state this problem correctly, and to give the solution of it. M. Broca compared 60 Europeans with 35 Negroes. Representing thetotal projectionby 1000, he found that in the former theanterior projectionwas 475, and in the latter 498. The anterior border of the foramen magnum is then further removed from the alveolar border in the Negro than in the White, the difference being 23. But this projection includes, with theanterior cranial projection, thefacial projection, which is 65 in the European and 138 in the Negro. If this is deducted from the former, we find that the White stands first incranial projection alone, and that the difference is 50.
We learn from these calculations that, relatively to the cranium to which it belongs, the foramen magnum is placed more forward in the Negro than in the White, which is by no means the case in apes. These same calculations demonstrate the real difference which here distinguishes the two, that, namely, of the forward prolongation of the face.
In drawing comparisons between men and apes, thesphenoïdal anglediscovered by M. Virchow, studied by M. Welker, and which, thanks to M. Broca, may be measured without making a section of the skull, presents special interest. It presents an inverse evolution in man, and the Quadrumana during growth. This may be seen from the annexed calculations borrowed from M.Welker:—
I have already insisted that facts of this nature are irreconcilable with those theories which attribute a more or less pithecoid ancestor to man.
In discussing the cranial cavity, our special object is to supply the deficiency of information upon the volume and weight of the brain. Now, from this point of view, we may easily fall into error. The bony cabinet and its contents are developed, to a certain extent at least, independently. This is very clearly demonstrated by a fact which was observed by Gratiolet, and is too frequently forgotten. The subject is an infant in whom the cranium presented the normal conformation. The brain was, nevertheless, almost entirely wanting. In well-formed men the sinuses and coverings of the brain may very easily be more or less developed according to the individual or race, and influence the relative dimensions of the brain.
Moreover, the exact measurement of the capacity of the cranium is attended by difficulties which have not yet been entirely surmounted. In spite of the improvements introduced by M. Broca in his method of measuring with shot, consecutive measurements of the same cranium by the same observer will vary considerably in the result.
Again, there are peculiarities to be taken into consideration, the importance of which has long been neglected. We have known for several years that the stature has an influence upon the weight of the brain. It cannot be without influence upon the cavity by which the latter is enclosed. M. Broca has shown that sex is of itself a cause of variation. In the woman the mean cranial capacity is always lessthan in the man, and the difference varies between different races.
Nevertheless, in examining a sufficient number of skulls, the causes of error may counterbalance each other, and the means may be accepted as giving results sufficiently near the truth. The results obtained by the same observer are especially favourable for comparison, and from them certain results may be obtained. There is no reason, therefore, why the cranial capacity should not be considered as a character well worthy of study. But its importance must not be exaggerated.
M. Broca arrived at the following result, in considering the distinction of extreme races. The cranial capacity of the Australian being represented by 100, that of the African Negro is 111·60, and that of fair European races 124·8.
I borrow from my eminent colleague the following table, published by M. Topinard in hisAnthropologie. This table gives the mean cranial capacity, in cubic centimetres, for a certain number of races in both sexes. I have merely substituted the serial order in the men for the almostgeographical division of the author, and calculated the difference between the sexes.