STANDARD BASAL METABOLISM CONSTANTS. 239 



for this difference between boys and girls we have no suggestion to 

 offer. It emphasizes the need for more numerous and more minutely 

 recorded data. 



It appears that the metabolism is much higher in boyhood than in 

 manhood, but in passing we must note that practically all of Magnus- 

 Levy and Falk's determinations are higher than the American stand- 

 ard. Thus the values of their constants for youth are probably too 

 high (when used in connection with American values for adults) for 

 the plotting of a curve of metabolism throughout life, as has been done 

 by Du Bois. 14 



To avoid all possible misunderstanding concerning the line of 

 reasoning employed in this section, we may reiterate that the age factor 

 in these immature subjects has for purposes of investigation been 

 assumed to be given by an extension of the line found valid for the 

 period of adult life. If the measured metabolism of the growing sub- 

 jects is higher than the value predicted by the standard equation for 

 adult life, we conclude that (if all sources of experimental error were 

 ruled out) the decrease in metabolism rate is much more rapid in the 

 period of growth than in the period of maturity. This seems to be 

 the indication of the series of measurements by Du Bois 15 and Magnus- 

 Levy and Falk. 



To show how large an influence correction for age by the adult 

 formula has had upon these metabolism constants we have predicted 

 the metabolism of the young subjects by means of the equations for 

 adult life ignoring the influence of age changes during adult life itself. 

 The equations are l 



For all men fe = -314.613 + 13.129 u;+6.388s 



For all women h= 713.016+ 8.063 w+1. 116s 



The results are given in table 95. The first difference column shows 

 that the age term in our equations has made a difference in the predicted 

 value of from 74 to 199 calories per 24 hours. 



The second section of the table shows the percentage excess of the 

 measured over the theoretical heat-production when the latter is 

 computed in the two ways. Here there is an influence not merely of 

 the actual differences in calculated and measured heat-production, but 

 of the theoretical heat-productions used as bases for the calculation 

 of the percentage excesses. 



14 Du Bois, Am. Journ. Med. Sci., 1916, 151, p. 781. Also Stud. Dep. Physiol., Cornell 

 Univ. Med. Bull., 1917, 6, No. 3, part II, p. 1. 



15 Just as this manuscript was being completed for the press, a second paper on the same sub- 

 jects appeared (Olmstead, Barr and Du Bois, Arch. Intern. Med., 1918, 21, p. 621). In this 

 investigation they find that the boy scouts had shown a material decrease in metabolism during 

 the two years since they were last studied. The influence of a small breakfast upon metabolism 

 has also been investigated (Soderstrom, Barr, and Du Bois, Arch. Intern. Med., 1918,21, p. 613), 

 and the authors conclude that it has no significant influence upon the metabolism constant. 



16 See Chapter VI, p. 184. 



