DURING POST-NATAL DEVELOPMENT. 491 



height in centimeters as an index of "Korperfiille." Its value has been recognized 

 by Martin in his Anthropologie (1914). It has, however, been but comparatively 

 little used. Bobbitt (1909) makes use of the reciprocal index and divides the cube 

 of the height by the weight. In tables D and E both the inch-pound and the centi- 

 meter-gram units are used to illustrate the ratio of weight to height in connection 

 with the data of Weissenberg and of Quetelet on linear proportions. 



Alterations in volume. The relation of volume to the cube of the stature 

 during three periods of development (infancy, childhood, and adolescence) and the 

 associated proportions of the body are illustrated in figure 1 . The figure at the left 

 is that of an infant about 2 weeks old, 21 inches long, weighing 8.5 pounds. The 

 middle figure is that of a well-developed child 5 years old, 42 inches long, weighing 

 39.3 pounds. The figure at the right is that of a youth 15 years old, 63 inches tall, 

 weighing 104.5 pounds. The figure of the infant is placed within an oblong block 

 21 inches high, 4 inches wide, and 3 inches deep. Each of the smaller squares on the 

 surface of the block represents a square inch. The volume of the infant is estimated, 

 at 27 cubic inches to the pound, to be 229.5 cubic inches. The volume of the block 

 in which it stands is 252 cubic inches. The ratio of volume of infant to volume of 



cube of stature is = 0.02478. The height- weight index is 5%^= 0.9178. 



y . ^01 



The figure of the child is at twice the scale of that of the infant. It is placed 

 within an oblong block 42 inches high, 6 inches wide, and 5 inches deep. Each of 

 the smaller squares on its surface represents 4 square inches, or a cube of 8 cubic 

 inches. The volume of the oblong block is 1260 cubic inches. The volume of the 

 child's body is 1061.1 cubic inches. The volume of the cube of the height is 74,088 

 cubic inches. The ratio of the volume of the child's body to the cube of its stature 

 is ^l- 1 = . 014322. The height-weight index is J? = . 53045. 



74Uoo /4.UOO 



The figure of the youth is at three times the scale of that of the infant. It is 

 placed within an oblong block 63 inches high, 9 inches wide, and 5 inches deep. Each 

 of the smaller squares on its surface represents 9 square inches or 27 cubic inches, 

 i. e., one "flesh" pound. The volume of the oblong block is 2835 cubic inches. The 

 volume of the youth's body is 2821.5 cubic inches. The volume of the cube of the 

 stature is 250,047 cubic inches. The ratio of the volume of the youth's body to 



the cube of the height is = . 01 1284. The height- weight index is -| ^- =0.418. 



' 



On comparing the height-weight indices of the three figures we see that that 

 of the infant, 0.918, is nearly 75 per cent greater than that of the child, 0.530; 

 while that of the child is only about 25 per cent greater than that of the youth. It 

 is also obvious that the figure of the child much more nearly resembles that of the 

 youth than that of the infant. The changes in the relations of volume to cube of the 

 height are associated with changes in the proportions of the body, which are far 

 greater during the first 5 years after birth while the child is growing 21 inches in 

 height than during the next 10 years when he grows another 21 inches in height. 

 The latter are, however, in the same direction in both cases, and the most striking 

 features are the decrease in the relative volume of the head and the relative increase 

 in the relative volume of the inferior extremities. The relative volumes of the trunk 

 and upper extremities change comparatively little. The relative volumes of the 



