268 Basal Metabolism in Men 



time. This may be shown to be the case by determining th 

 average values of the standard deviations of the metabolism ( 

 the groups of individuals for whom the correlations in Table 1 

 were calculated. These means have been calculated for th 

 groups of 19 to 101 subjects with the range indicated in Table 

 and for the individuals added to each group to give the next wide 

 range group. These mean standard deviations are shown in th 

 last two columns of Table V. The first series is represented i 

 Fig. 1 by the circles connected by continuous lines while the sec 

 ond is shown by the circles connected by broken lines. Th 

 wide variability of the latter averages is attributable to the ver 

 small number of individuals added in the longer range periods. 1 

 Both series of means show that the standard deviation at firs 

 increases rapidly as the length of the period becomes longer bu 

 the rate of increase becomes smaller as the periods over whicl 

 the observations extend increase in length. 



The last paragraph on page 264, written as it stands befor 

 the calculation of the constants in this table, is therefore full; 

 substantiated by the available data for individuals who have bee 

 studied over longer periods of time. 



8. The Statistical Constants for Basal Metabolism in Man. 



A primary requisite for continual progress in the investigatio 

 of human metabolism under various special conditions, e.g. c 

 exercise, rationing, or disease, is the determination of some stanc 

 ard which may serve as a basis of comparison. 15 Such a cor 

 stant, based upon a considerable series of individuals and designe 

 to serve as a standard of comparison, may be conveniently desij 

 nated as a population constant. 



The average value of the basal metabolism constant has gene: 

 ally served this purpose, whether expressed in actual calori( 

 per unit of time uncorrected for the influence of body mass, i 

 calories per kilo of body weight, or in calories per square met( 



14 In the twelve groups in which the range is wider than 2-360 days tl 

 positions of the circles represent the standard deviations for single ind 

 viduals only, not means. 



15 The general principles underlying the establishment of control seri 

 have been discussed elsewhere (Harris and Benedict, 1 pp. 223-227; 

 Harris and Benedict, 3 p. 385). 



