772 REPORT— 1897. 



butes of the human form from its beginning', there can be little doubt that this 

 power is potential in the human organism at the time of birth, and only requires a 

 further development of the nervous and muscular systems to become a reality, 

 without the aid of any special training. 



The spinal column in the region of the true vertebrae consists of numerous bones 

 jointed together, and with discs of soft fibro-cartilage interposed between and 

 connecting the bodies of adjoining vertebrae with each other. It is to their 

 presence that the spinal column owes its flexibility and elasticity. These discs 

 are larger and thicker in the region of the loins, where the lumbar convexity is 

 situated, than in other parts of the column, and there can be no doubt that the 

 acquisition of this convexity is intimately associated with the presence of thesa 

 discs. 



It is a matter for observation and consideration to what extent the bodies of 

 the vertebrae contribute to the production of this curve. A few years ago Professor 

 Cunningham, of Dublin,^ and I^ undertook much about the same time researches 

 into the form and dimensions of the bodies of these bones. Our observations were 

 made independently of each other and on two different series of skeletons, and as 

 we arrived at practically the same conclusions, we may, I think, infer that, in their 

 main features at least, these conclusions are correct. 



The method followed in the investigation was to measure the diameter from 

 above downwards of the body of each of the five lumbar vertebrae, both in front 

 and behind. If the upper and lower surfaces of the bodies of the vertebrae were- 

 parallel to each other, it is obvious that, so far as they are concerned, the column 

 formed by them would be straight, as is the case in a column built of hewn stones 

 possessing similar parallel surfaces. But if the surfaces are not parallel the body 

 of the vertebra is wedge-shaped ; should the front of the collective series of bones 

 have a greater vertical diameter than the back, it is equally obvious that the- 

 column would not be straight, but curved, and with the convexity forwards. From 

 the examination of a considerable number of spinal columns of Europeans, we found 

 that, although the vertical diameter of the bodies of the two highest vertebrae was 

 greater behind than in front, in the two lowest the anterior vertical diameter 

 so greatly preponderated over the posterior that the anterior vertical diameter of 

 the bodies of the entire series of lumbar vertebrae in each spine was collectively 

 greater than the corresponding diameter of the posterior surface. In twelve 

 European skeletons I observed that the mean difference was between 5 and 6 mm. 

 in favour of the anterior surface. If we are to regard the collective vertical 

 diameter anteriorly of the five bones as equal to 100, the same diameter posteriorly 

 is only equal to 96, which may be regarded as the lumbar index in Europeans. 

 Dr. Cunningham obtained a similar index from the examination of a much larger 

 number of European skeletons, and he further showed that in women the lumbar 

 convexity forwards is more pronounced than in men. It follows therefore, from 

 these observations, that when the broad end of the wedge-shaped bodies is in front 

 the bones themselves would by their form give a forward convexity to the spine in 

 the lumbar region. But a similar wedge-shaped form is also possessed by the 

 lower intervertebral discs in this region, and especially by that interposed between 

 the last lumbar vertebra and the sacrum. Hence it follows that both vertebral 

 bodies and intervertebral discs contribute in the white races to the production of 

 the lumbar convexity. 



When we pass to the examination of the corresponding region in the spines of 

 those races of men that we are accustomed to call lower races, we find a remarkable 

 and important difference. Let us take as a characteristic example of a lower race 

 the aborigines of Australia. In their skeletons our observations have proved, that 

 the vertical diameter of the bodies of the five lumbar vertebrae 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 

 opposite condition to that which prevails in Europeans. Hence if the spine had 



' ' The Lumbar Curve in Man and the Apes,' Cunningham, Memoirs of the Boyat 

 Irish Academy, Dublin, 1886. 



2 ' Report on Human Skeletons,' Challenger Bejwrts, Part XLVII., 1886. 



