THE PHYSICAL CHARACTERS OF THE RACES OF MANKIND. 1. THE PROPORTIONS OF THE SKULL. Ir is universally admitted that domestic animals by careful selecttion transmit all parental peculiarities to their offspring. In the same manner a human tribe, scanty in number, which in old times separated itself from the rest of mankind by migration, remaining for thousands of years in a remote region of the world, was, as it were, constrained by circumstances to preserve the purity of its breed, thus necessarily developing the family features of the first emigrants into racial characteristics. But the purity of the acquired type was preserved only as long as the seclusion lasted. As the single tribes and families before and even after their adoption of agriculture were constantly in a state of migration, one variety mingling with the other, some of the distinctive characters were necessarily obliterated by intercrossing; for the infertility of crosses between human varieties cannot be proved. At most therefore we must hope to meet with even moderately well-defined races only in those cases in which, either by the remoteness of their abode, or the precepts of caste, a separation from other varieties has been maintained during long periods; everywhere else they will merge into one another. It may be shown that no one physical characteristic belongs exclusively to any single race, but that each may be found in a transitional state in other races. Hence ethnological description must deal with many distinctive marks, and must not despise any, however much they may vary in degree. In seeking characteristics of the human frame, such as serve to mark difference of race, we instinctively look in the first place to the shape of the head, the seat of our highest functions. The industry and ingenuity of modern anatomists have therefore developed a new branch of science devoted to the bones of the skull. A death's head, as it is vulgarly called, is a skilfully arranged case, narrower and smaller in the head of a child, more capacious in adults. It must therefore expand until a certain age, and cease to grow only in mature years. The separate bones of the brain-case, where their edges come in contact, are usually joined only by sutures with serrated notches, so that no insuperable impediment opposes the continued growth. A premature consolidation of the cranial bones must, on the contrary, prevent the full development of the brain; hence, if an obliteration of the sutures is observed in youthful crania, these heads are abortive formations. Now, as science is bound to compare only normal phenomena, it follows that we must exclude the measurements of all skulls of which the sutures are prematurely effaced or, what amounts to the same, become anchylosed. One of the plates of the skull, i.e., the frontal bone, consists originally of two halves, a right and a left, which in apes become completely anchylosed after birth, in children in the second year. In many cases, however, they never close, and as in that case the frontal suture, being a prolongation of the sagittal suture, bisects the coronal suture at right angles, the course of the sutures forms a cross, whence skulls in which the frontal suture is open are termed in German, Kreuz-köpfe. These also, as the representatives of a peculiar form to be compared only with each other, must be excluded from our list of measurements. The disjunction of the frontal suture in no way injures the normal functions of the brain; rather, as it admits of its growth forwards to a later age, the skulls with open frontal sutures combine greater width of brow with greater capacity, so that it has even been conjectured that the average efficiency of man's intellectual power would be raised if the permanent disjunction of this suture were to become the prevailing character of the normal cranium. In connection with the frequency of cross-heads, Hermann Welcker has furnished us with the following statistics : Other observers are of opinion that skulls belonging to the diluvial period more rarely exhibit this favourable character.1 But if the forehead remains open, the sagittal suture generally closes later, and we are to a certain extent justified in supposing that an endeavour on the part of the brain to find room may be the cause of this phenomenon,2 yet we ought not to forget that frontal bones with open sutures also occur occasionally in idiots.3 But, on the other hand, the full development of the brain may be impeded by the premature anchylosis of the bones if it proceeds in such a manner as to overcome the counter-pressure.4 In the less gifted races the anterior, in the more highly gifted the posterior sutures are said to be earliest obliterated.5 In the skulls of negroes, Pruner Bey thought he had perceived a premature closure of the frontal suture, followed by the anchylosis of the sagittal and of the middle portion of the coronal sutures, while the lambdoidal suture at the summit remained open the longest. Occasionally even the basilosphenoidal suture does not completely unite, while even in adults the incisive suture 1 Canestrini. See Darwin's Descent of Man, vol. i. p. 125. 2 Hermann Welcker, Wachsthum und Bau des menschlichen Schädels, pp. 97-102. Leipsic; 1862. * Virchow, Entwickelung des Schädelgrundes, p. 87. Berlin, 1857. • Virchow, l.c. p. 13. s Gratiolet. See Quatrefages, Rapport, p. 302. E |