The Spinal Curvature in an Aboriginal Australian. 491 



were very remarkable, and altogether confirmed the view which I had 

 formerly expressed upon this point from an examination of the cervical 

 neural spines of the native Australian.* 



In order that precise information regarding the curvatures might 

 be acquired, the spine was thoroughly frozen, and then divided in the 

 mesial plane with a saw. A very successful section was obtained, 

 and when the spine was still in the frozen condition, with all its parts 

 immovably fixed, a tracing was taken of each cut surface, and the 

 intervertebral disks and vertebral bodies were measured. At 

 intervals the spine was returned to the freezing mixture, so as to 

 keep it thoroughly consolidated until all the details required were 

 ascertained. 



In the accompanying woodcut the tracing of the spine section, 

 reduced by photography, is represented. Similar tracings taken from 

 the spines of an Irish female, aged thirty-five, and a young female 

 Chimpanzee, reduced to a corresponding size, are placed on either side 

 of the Australian spine for purposes of coiriparison. 



The flatness of the dorsal curve in the Australian is very pro- 

 nounced, and is more marked than in the Chimpanzee, in which both 

 of the primary curvatures (dorsal and sacral) are notably deficient. 

 It further resembles the Chimpanzee in the high degree of cervical 

 curvature which it exhibits. 



Points of Inflexion. In determining these we have not examined the 

 curvature formed by the anterior face of the vertebral column. The true 

 curvature of the vertebral column is that of its axis, and it is this that 

 we have tested. The central points of the bodies of the vertebras and 

 of the intervertebral disks were carefully ascertained, and a mean 

 curve was drawn through them. In European spines the point at 

 which each curve gives place to that which succeeds it is very 

 constant, and is not affected, so far as my observations go, by the 

 degree of curvature in the different regions. The cervico-dorsal point 

 of inflexion in the European is situated in the disk between the 

 second and third dorsal vertebras. The lumbo-dorsal point of inflexion 

 in the female is placed in the body of the twelfth dorsal vertebra, but 

 in the male it is a little lower down. The lumbar curve gives place to 

 the sacral curve at a point in the lumbo-sacral disk. 



In the Australian spine a greater portion of the dorsal column is 

 involved in the dorsal curve. Above, this curvature only gives way to 

 the cervical convexity in the disk between the first and second dorsal 

 vertebrae, whilst below it includes the last dorsal vertebra, as in the 

 European male, and the change to the lumbar convexity is effected in 

 the dorso-lumbar disk. 



These are points of comparatively trifling importance. The great 

 distinction between the Australian and European spine is found in the 

 * ' Journal of Anatomy and Physiology,' July, 188(3. 



