TKANSACTIONS OF SECTION U. 773 



been constructed of vertebras 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 ' Koilorachic' 



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 Professor 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 vertebrae were longer than in Europeans, the proportion of inter- 

 vertebral 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 vertebrae, 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 vertebrae behind than 

 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, 

 Andaman 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 produc- 

 tion of the lumbar curve than in Europeans. 



One of the requirements 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 there- 

 fore 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 convexity in the spinal 

 column was the exclusive privilege of man, and was shared in by no other verte- 

 brate. 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 observations of 

 ■Cunningham on the spinal column of apes, more especially the anthropoid group, 

 made in i'resh specimens, in which the intervertebral discs were in place, have 

 proved that in the Chimpanzee the lumbar convexity is probably as strongly pro- 

 nounced as in the adult man. In a Chimpanzee, two years old, the development 

 is more advanced that in a child of the same age. The lumbar convexity is 

 «stabhshed at an earlier age than in the child, for it would seem as if the Chim- 

 panzee 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 by the same anatomist, the 

 lumbar curve was intermediate between the Chimpanzee and the Orang. 



In 1888, 1 purchased the bones of an adult male Gorilla, in which the vertebrae 



' Proc. Eoy. Soc. London, January 24, 1889, vol. xlv. ; also see Journal of Anatomy 

 aid Physiology, vol. xxiv. 1890. 



