428 



NA TURE 



[Seitkmber 2. 1897 



lower races, we find a remarkable and important diticrence. 

 Let us take as a characteristic example of a lower race the abori- 

 gines of Australia. In their skeletons our observations have 

 proved, that the vertical diameter of the bodies of the five lumbar 

 vertebra; was collectively deeper behind than in front. In my 

 series of skeletons the mean difference was between 6 and 7 mm. 

 in favour of the posterior surface, so that they possessed the op- 

 posite condition to that which prevails in Europeans. Hence if 

 the spine had been constructed of vertebnie only, instead of 

 a lumbar convexity, the column would have possessed a forward 

 concavity in that region. For this character, as shown in the 

 skeleton only, I have suggested the descriptive term " Koilo- 

 rachic." 



We know, however, that elastic discs are intercalated between 

 the bodies of the osseous vertebrae in the black races as well as 

 in Europeans. It is necessary, therefore, to examine their 

 spinal columns, when the intervertebral discs are in position, 

 in order to obtain a proper conception of the character of the 

 •curve in the living man. 



A few years ago Prof. Cunningham had the opportunity of 

 studying the spinal column of an aboriginal Australian,^ in 

 which the intervertebral discs had been preserved in their proper 

 position, in relation to the bones, without losing their flexibility, 

 or their natural shape and thickness. He found that, whilst the 

 bodies of the lumbar vertebn^ were longer than in Europeans, 

 the proportion of intervertebral disc to vertebral body was 

 distinctly less, so that the disc appeared to be reduced in depth, 

 in relation to the greater vertical diameter of the vertebral body. 

 Notwithstanding this difference, as compared with the white 

 man, the Australian spine had a marked lumbar convexity which 

 showed no material difference from that seen in Europeans. As 

 the lumbar curve was not due to the wedge-shaped form of the 

 bodies of the vertebme, it was therefore produced solely by the 

 strong wedge-shape of the intervertebral discs, and was not, as 

 in Europeans, a product of a combination of both these factors. 

 The spinal column, when complete, is not therefore koilorachic 

 in the lumbar region. 



The greater vertical diameter of the bodies of the lumbar 

 vertebra; behind them in front, as compared with Europeans, is 

 not limited to the Australians, but is participated in by other 

 black races, as the now extinct Tasmanians, the Bushmen, An- 

 daman Islanders, and Negroes, which, if tested solely by the 

 measurements of the skeleton,, would also be koilorachic. But 

 in these races intervertebral discs are also present, and there 

 can be no doubt that through the compensating influence of the 

 wedge-shaped discs, with their deeper ends in front, the lumbar 

 curve is in them also convex forwards. It is clear, therefore, 

 that in the black races the intervertebral discs play relatively a 

 more important part in the production of the lumbar curve than 

 in Europeans. 



One of the acquirements of civilisation is the wearing of 

 clothes, and fashion frequently prescribes that they should be 

 tight-fitting and calculated to restrict motion in and about the 

 spinal column. In savage races, on the other hand, clothing is 

 often reduced to a minimum, and when worn is so loose and easy 

 as in no way to hamper the movements of the body. The spinal 

 column retains therefore in them much more flexibility, and 

 permits the greater measure of freedom in the movements of the 

 trunk, which is found in savage man, and has often been referred 

 to by travellers. 



It used to be considered that the possession of a lumbar con- 

 vexity in the spinal column was the exclusive privilege of man, 

 and was shared in by no other vertebrate. There can be no 

 doubt that it attains a marked development in the human spine, 

 and as such is associated with the erect posture. But the ob- 

 servations of Cunningham on the spinal column of apes, more 

 especially the anthropoid group, made in fresh specimens, in 

 which the intervertebral discs were in place, have proved 

 that in the Chimpanzee the lumbar convexity is probably as 

 strongly pronounced as in the adult man. In a Chimpanzee, 

 two years old, the development is more advanced than in a 

 child of the same age. The lumbar convexity is established 

 at an earlier age than in the child, for it would seem as if 

 the Chimpanzee attained its maturity at a younger period of 

 life than the human being. In the Orang the lumbar curve 

 is more feeble than in Man and the Chimpanzee, and in the 

 specimen described by Cunningham resembled that of a boy 

 six years old. In a fresh specimen of the Gibbon, examined 



1 Proc. Roy. Soc. London, January 24, 1889, vol. xlv. ; aXso see Journal 

 «f Anatomy and Physiology, vol. xxiv. 1890. 



NO. 1453. VOL. 56] 



by tile same anatomist, the lumber curve was intermediate be- 

 tween the Chimpanzee and the Orang. 



In 1888, I purchased the bones of an adult male Gorilla, in 

 which the vertebrre were in position and connected together by 

 the dried intervertebral discs. This condition is of course not so 

 satisfactory, for the study of the spinal curves, as if the specimen 

 had been fresh, and with the discs retaining their natural flexi- 

 bility and elasticity. But it was quite obvious that the spine 

 possessed an alternating series of convex-concave curves from 

 above downwards. The cervical and lumbar convexities, more 

 especially the latter, did not project so far forwards as in man, 

 and the dorsal concavity was not so deep. The most projecting 

 part of the lumbar convexity was at the junction of the bodies 

 of the third and fourth lumbar vertebras and their intermediate 

 disc. A vertical line drawn downwards from the most pro- 

 minent part of this convexity fell in front of the coccyx. When 

 prolonged upwards it passed in front of the bodies of the dorsal 

 vertebrre, and intersected the body of the sixth cervical vertebra, 

 so that the bodies of the vertebrae, higher than the sixth, were 

 directed obliquely from below upwards and forwards in front of 

 the vertical line. 



The dried state of the discs did not enable one to determine 

 precisely the proportion in which they entered into the formation 

 of the length of the column, but the vertical diameter of the 

 interlumbar and lumbo-sacral discs was obviously not as great 

 as in the human spine. On the other hand, the vertical diameter 

 of the bodies of the lumbar vertebrae was greater than in man, 

 so that the length of the lumbar spine, and possibly its degree 

 of convexity, were due more to the bodies of the vertebra than 

 to the elastic discs interposed between them. The Gorilla 

 corresponds with the Chimpanzee in having longer vertebral 

 bodies and shorter intervertebral discs than in man. 



Without going into the question whether a lumbar convexity 

 exists in the tailed monkeys, the determination of which with 

 precision is a matter of some difficulty, it must be obvious that 

 the presence of this convexity can no longer be regarded as the 

 exclusive prerogative of man. It undoubtedly forms an im- 

 portant factor in the study of the erect attitude ; but in order 

 that man should acquire and be able to retain his distinctive 

 posture, something more is necessary than the possession of a 

 spinal column with a curve in the lumbar region convex for- 

 wards. 



Our attention should now be directed to the lower limbs, 

 more especially to the two segments of the shaft, which we call 

 thigh and leg. 



If we look at a quadruped we see that the thigh is bent on 

 the trunk at the hip joint, and that the leg is bent on the thigh 

 at the knee joint ; whilst the foot forms more or less of an angle 

 with the leg, and the animal walks either on the soles of its 

 feet or on its toes. In the Anthropoid apes there is also distinct 

 flexure both of the hip and knee joints, so that the leg and thigh 

 are set at an angle to each other, and the foot is modified, 

 through a special development of the great toe, into an organ 

 of prehension as well as of support. When we turn to the 

 human body we find that in standing erect the leg and thigh are 

 not set at an angle to each other, but that the leg is in line 

 with and immediately below the thigh, that both hip and knee 

 joints are fully extended, so that the axis of the shaft of the 

 lower limb is practically continuous with the axis of the spine. 

 The foot is set at right angles to the leg, and the sole is in 

 relation to the ground. The vertical axis of the shaft of the 

 lower limb, the extended condition of the hip and knee joints, 

 and the rectangular position of the foot to the leg are therefore 

 fundamental to the attainment of the erect attitude of man. 



In narratives of travel by those who have studied the Penguins 

 in their native habitats, you may read that these birds may be 

 seen standing on the rocks on the coasts which they frequent, 

 in rows, like regiments of soldiers, and the idea has become 

 implanted in the minds of many that they can stand erect. 

 Even so accomplished a writer and acute a critic as the late 

 Mr. G. H. Lewes thought that the Penguins had the vertical 

 attitude when standing, and that some mammals, as the Jerboa 

 and Kangaroo, very closely approached to it. The attitude of 

 man was, he considered, merely a question of degree, and did 

 not express a cardinal distinction.^ 



In arriving at this conclusion, however, only the external 

 appearance of the birds and mammals referred to by him can 

 have been looked at. If the skin and flesh be removed, and 



1 Aristotle, "A Chapter from the History of Science," p. 309, London 



