GROWTH. 63 



PHYSIOLOGICAL AND ANTHROPOMETRICAL SIGNIFICANCE OF SURFACE AREA. 



Studies of the body-surface measurements of children have been 

 prompted primarily from an attempt to correlate the total heat pro- 

 duction of children with some physical factor. The apparent dis- 

 crepancy between the heat production per kilogram of body-weight 

 and the total weight of the child at various ages early led to an effort 

 to secure, if possible, a uniform basis for comparison of children and 

 adults, i. e., individuals of greatly differing weights, and it was believed 

 that the heat production per unit of body-surface was much more 

 nearly constant than the heat production based either upon the 

 body-weight or any other factor; in fact, so constant as to represent a 

 " physiological law." The extensive series of body-surface measure- 

 ments made by us were admittedly secured primarily in connection 

 with a study of the possible relationship between heat production and 

 body-weight on the one hand and heat production and body-surface 

 on the other. A recent critical analysis of the so-called " body-surface 

 law" appearing from this laboratory 1 vitiates, we believe, to a very 

 large degree, the significance of this "law," particularly that part of it 

 which recognizes a causal relationship between the surface area and 

 the heat production. Our present position on this point can be no 

 better set forth than by repetition of an opinion expressed six years 

 ago 2 to the effect that we believe body-surface has no significance in 

 connection with heat production, except that it represents a general 

 morphological law of growth. 



We have, however, a series of carefully measured surface areas of 

 children of varying ages. That these measurements are of direct 

 physiological and anthropometrical importance is undoubtedly true. 

 Thus, the marked changes appearing in the general configuration of 

 the growing child as compared with the adult are familiar to all. 

 Are these changes accompanied by disturbances in the general rela- 

 tionship between surface area and body-weight, or surface area and 

 height, or surface area and age? This question can be adequately 

 answered only by graphic presentation of our data. 



RELATIONSHIP BETWEEN SURFACE AREA AND BODY-WEIGHT, HEIGHT, AND AGE WITH BOYS. 



Since these surface areas are all actually measured according to the 

 Du Bois linear formula and are not computed from the body-weight, 

 it seems perfectly justifiable to plot them against age, height, and 

 body-weight, and this we have done in the six following charts for 

 both boys and girls. 3 Thus, in figure 9 we have plotted the body- 



1 Harris and Benedict, Carnegie Inst. Wash. Pub. No. 279, 1919, p. 129. 



2 Benedict and Talbot, Carnegie Inst. Wash. Pub. No. 201, 1914, p. 168. 



3 See tables 26, 27, and 28 (pp. 112, 116, and 120) and tables 12 and 13 (pp. 54 and 58) for data 



plotted on these charts. It will be noted that in 20 instances with the very young boys and 

 in 19 instances with the very young girls the surface areas have been computed from the 

 Lissauer formula, since the Du Bois measurements were not made in these cases. We feel 

 justified in plotting these values on our charts, however, since we have demonstrated the 

 remarkably close agreement between the surface-area measurements obtained by the 

 Lissauer formula and the Du Bois linear formula for young children. 



