The Spinal Curvature in an Aboriginal Australian. 495 



processes. It is possible, therefore, that the tendency to assume 

 sacral characters is more marked in the last lumbar vertebra of the 

 Australian than of the European.* 



Lumbar Curve. A single glance at the tracing obtained from, 

 the mesial section of the Australian spine, and which has been 

 reproduced in fig. 1, will be sufficient to dissipate any doubt 

 that may be remaining regarding the presence of a lumbar convexity 

 in the vertebral column of this race. Not only does it exist, but 

 it is present in a very* pronounced form. Sir William Turner, who 

 has studied the lumbar vertebras of several of the low races, has 

 endeavoured to arrive at the proper lumbar curvature by careful 

 articulation of the vertebras. ** The upper border of the superior 

 articular facet of the vertebra below was placed in the same trans- 

 verse plane as the upper border of the inferior articular facet of the 

 vertebra above."f In the Australian he was led to believe that above 

 the level of the lower border of the fourth lumbar vertebra the 

 lumbar column was faintly concave forwards. At the same time he 

 carefully guards himself by insisting that true and trustworthy 

 evidence upon this point can only be acquired by the actual exami- 

 nation of the fresh spine. 



A convenient although a somewhat arbitrary way of determining 

 the degree of prominence in the lumbar region in sectional tracings 

 of the spine is to draw a straight line from the anterior extremity 

 of the lower surface of the last lumbar vertebra to the anterior end of 

 the upper surface of the first lumbar vertebra (vide fig. 1). By the 

 eye we can readily judge the amount of projection which lies in front 

 of this line in the different tracings, but for accurate comparison it is 

 advisable to formulate an index. This can be done by taking the 

 length of the lumbar column (measured from the centre of the upper 

 surface of the first lumbar vertebra^ to the centre of the lower 

 surface of the last lumbar vertebra), as the standard and equivalent 

 to 100, and then comparing it with the distance between the inter- 

 secting line and the point of greatest prominence. A high index 

 will indicate a strongly pronounced curve, and a low index a feeble 

 degree of curvature. The indices of the lumbar curve ascertained in. 

 this way from the three tracings in fig. 1 are the lollowing : 



European. Australian. Chimpanzee. 



97 9-6 10-0 



* In twelve Australian skeletons which I have recently examined in the Museum 

 of the Boyal College of Surgeons, England, the condition is only present in one 

 specimen. 



t ' Zoology of the Yoyage of H.M.S. " Challenger," Part XL VII,' &c. 



The vertebra, corresponding to the first lumbar vertebra of Man in the Chim- 

 panzee, is the thirteenth dorsal. .* I 



