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LABORATORY MANUAL OF ANTHROPOMETRY 



a straight one than in man. The position of the point of greatest curva- 

 ture, as indicated by Index C, varies with the amount of curvature, lying 

 farther back (more posteriorly) when the curve is deeper. This is indi- 

 cated by the larger numbers, which show that the line ac is longer. In 

 this particular the Fuegians have the highest number, and consequently 

 the most posterior position of any race yet studied, modifying the general 

 rule concerning the relation of curvature to position of the foot of the 

 perpendicular, for in these people the actual amount of curvature, 

 although great, is not quite that of the Europeans. 



(c) Transverse curvature indices. 

 Transverse cunature index A (4 : 3) 



Transverse curvature index B (6 : 5) 



anterior straight breadth X 100 

 anterior curved breadth 



middle straight breadth X 100 

 middle curved breadth 



These two indices consist merely of comparisons of the straight and 

 curved transverse diameters at respectively the anterior and middle parts 

 of the sacrum, and indicate the amount of curvature, or longitudinal 

 rolling, found in a given case. A similar index at the more posterior 

 part of the sacrum has no especial meaning, as there the ventral surface 

 of the bone is so flat that there is practically no difference between the 

 two measurements. For these two indices the following racial values 

 have been determined. 



VALUES OF TRANSVERSE CURVATURE INDICES [RADLAUER, 3941. 



Name of Race 



Transv. curv. 

 index A 



Transv. curv. 

 index B 



Lower apes 



Simian apes 



Australians, Oceanians 



Negroes 



Asiatics 



American Indians 



Europeans 



90.5 

 97.1 

 94.8 

 94.6 

 95.1 

 95.3 

 95.5 



97.3 

 97.3 

 97.8 

 97.4 

 97.9 

 98.0 



From these figures it will be seen that the sacrum is more nearly flat 

 at about the middle than at the upper level; also that the European 

 have the flattest sacra transversely, and the Australians and negroes the 

 most curved, along the same aspect. Taken as racial criteria the slight 

 difference shown here, which include the races of the greatest general 

 difference, gives us little to hope for in the use of these indices. Prob- 

 ably the actual value of these transverse curvature indices is but 

 slight . 



