206 A BIOMETRIC STUDY OF BASAL METABOLISM IN MAN. 



averaged constants of a group of women with the empirical average 

 of a group of men selected for their approximate agreement in stature 

 and body-weight, we compare the averages for the groups of women 

 selected for stature, body-weight, or both stature and body-weight, 

 or for stature, body-weight, and age with the smoothed or theoretical 

 averages for men of the specified physical dimensions. 



The method is essentially the same as that which has been followed 

 in certain preceding sections. We calculate the theoretical heat- 

 production of female individuals from constants based on the series 

 of men, and by comparison of the empirical means with the average 

 of the theoretical values we determine whether the women have a 

 higher or a lower metabolism than would be expected if they were men 

 of the same physical dimensions. 



For a first test of the existence of sexual differentiation we classify 

 the women according to (a) body-surface area as determined from the 

 Du Bois height-weight chart, (6) body-weight, (c) stature, and (d) age. 



The predicted total heat-production has been estimated by means 

 of the regression equations for total heat on physical characters and 

 age in the total male series. 12 



In using these equations we have started from the simplest and 

 advanced to the more complex, laying the results attained by each 

 of the methods before the reader, who may therefore trace the growth 

 of the underlying conceptions of our methods and convince himself that 

 the results due to the more complicated processes are not attributable 

 to some error in the more recondite reasoning. We first of all compare 

 the values of the metabolism constants actually obtained for women 

 with those which are calculated from their weight, from their stature, 

 and from their body-surface area considered independently of each 

 other and of age. Thus in working with body-surface we determine 

 whether women as a class have a higher or a lower basal metabolism 

 than men of the same superficial area. In doing this we disregard 

 body-weight, stature, and age. Similarly, in dealing with equations in- 

 volving constants for body-weight we disregard stature, body-surface, 

 and age. 



In the second attack upon the problem we base our predictions 

 of heat-production in women upon an equation involving the con- 

 stants for body-weight and stature in men. Thus body-surface (which 

 is of course largely determined by stature and weight) and age have 

 been disregarded. 



12 The analysis in Chapter VI has fully demonstrated the fallacy of predicting total heat- 

 production by multiplying body-weight or body-surface by the average heat-production per unit 

 weight or per unit surface in the standard series. We shall not, therefore, give the results of com- 

 parison on that basis further than to say that with individuals grouped according to body-weight 

 and body-surface area, as in tables 80 and 81, the average actual heat-production of the groups 

 of women is lower than that based on male constants in all the 12 subgroups classified with respect 

 to body-surface and lower than that calculated from the average production per kilogram of 

 body-weight in the men in 10 of the 13 groups of women classified according to body-weight. 



