128 LABORATORY MANUAL OF ANTHROPOMETRY 



Here the Neandertals are best compared with the Alamanni, in which 

 the absolute length is about the same, while the disparity in the dimen- 

 sions of the head are evident. That this large and heavy head is in some 

 way correlated with the great length of the proximal epiphysis, which 

 includes head and neck, is highly probable. 



III. ANGLES 



1 . Collo-diaphysial angle. This is the angle made by the axis of head 

 and neck with that of the shaft (of the bone as a whole). It is usually 

 measured by first placing steel needles along the bone to define the two 

 axes, and then measuring the angle made by their intersection by means 

 of a transparent, or other, protractor. 



As this angle varies at different ages, becoming more nearly a right 

 angle in senile femora, it should be used only through the middle part 

 of life, from maturity to perhaps the 60th year. The angle differs 

 markedly in the two human species, H. sapiens and H. neandertalensis, 

 being much greater in the former. Thus in Germans it averages 125.9°, 

 in Swiss, 133.°; and in Fuegians, 123.0°, while in Homo neandertalensis it 

 varies between 115° and 120°. 



2 Condylo- diaphysial angle. Stand several femora on the table, 

 on their distal ends, resting both condyles on the surface, and with the 

 bone extending vertically upward, and it will be noticed that the inclina- 

 tion of the bone to the surface of the table is not the same. This displays 

 practically the condylo-diaphysial angle, which is the angle between a 

 line drawn across the condyles distally and the axis of the shaft. As in 

 the former case these lines are determined by the eye, and marked by 

 steel needles, fixed to the bone by wax, or plastilene, while the angle is 

 read off by a protractor. It may be also measured by means of a specially 

 prepared osteometric board, upon which the bone is laid as in getting 

 the physiological length. This angle has been determined at 8° in 

 Fuegians, and 11° in Swiss. In H. neandertalensis it has been estimated 

 at 9°, quite within the range of variation of modern men. 



3 Angle of torsion; the angle formed by the axis of head and neck 

 projected upon that of the condyles, and is measured in the same way as 

 is the like-named angle in the humerus, by the parallelograph. If 

 found to be easier the two axes may be marked by applying steel needles 

 to the bone. The bone is then held vertically in a clamp, and the two 

 axes are drawn as projections upon a piece of paper placed on the table 

 underneath the suspended bone (see Fig. 11, p. 18). 



This angle shows great individual variation, but may be of some racial 

 value also. Thus Martin found in Fuegians a range of values between 

 6° and 38°, with a mean value of 18.3°. The right femur of the Neandcr- 

 tal skeleton has a torsion angle of 9.5°, and the same bone in Spy 1, 

 shows a value of 12°. 



