DURING POST-NATAL DEVELOPMENT. 



513 



Length of forearm. This is shown in chart I by the distance between the curve 

 for the elbow- joint and that for the wrist- joint. The former represents the top of 

 the radius, the latter the lower joint surface of the radius, not the tip of the styloid 

 process. The data of Quetelet (table E) show the distance from elbow-joint to 

 wrist- joint less than that shown in chart I, but the distance acromion to wrist-joint 

 is closely similar until maturity is approached, when it becomes slightly longer than 

 that shown in chart I. Godin (1910) gives lower values for length of forearm in 

 the younger boys of his series, about the same values for the older boys. The data 

 of Schwerz (1910) correspond closely with the curves in chart I for length of fore- 

 arm, but since he measured to the tip of the styloid process the length of the forearm 

 is relatively less. Both Quetelet and Schwerz show the female forearm shorter than 

 the male. The difference amounts to about 0.5 per cent of the stature. It is evident 

 after the fifth or sixth year. According to Godin (1910), the forearm attains its 

 greatest relative length at 16.5 years of age. It is 0.4 per cent of the stature longer 

 at 23.5 years of age than at 13.5 years of age. 



Length of hand. This is measured from the wrist joint to the tip of the middle 

 finger, "medius." Data on the relative length of the hand from birth to maturity 

 are given by Quetelet (table E) and by Weissenberg (1911). Daffner (1902) gives 

 a detailed comparison of the hand and feet of the new-born and adults. Godin 

 (1910) and Schwerz (1910) give data on the length of hand in school children. In 

 table K data are given for the curves in chart I. The relative length of the hand 

 there given for the new-born (12 per cent of the stature) is somewhat less than that 

 given by Weissenberg (males 12.6 per cent) and Quetelet (12.2 per cent for both 

 sexes). In the cases I have studied I have found the length slightly less than 12 per 

 cent and this is true of the few cases tabulated by Meeh (table B). For older chil- 

 dren, adolescents, and adults the relative hand-length shown in chart I corresponds 

 closely with Quetelet's data. It is somewhat greater than that of the younger chil- 

 dren recorded by Schwerz and that of the Godin adolescents. In part this is due to 

 basing the curve on the wrist-joint rather than on the tip of the styloid process. 

 The hand decreases slightly in relative length from birth to maturity. There 

 appear to be no well-marked sexual differences in length of hand relative to stature. 

 Relative to width of hand, the female hand is narrower (Daffner, 1902). 



Segmental proportions. The relative lengths of the various segments of the 

 upper extremity to the extremity as a whole in the infant and adult are shown 

 approximately in the accompanying table. 



TABLE 15. 



