METABOLISM AS AFFECTED BY GROWTH. 



167 



We believe that this is the first time that actually measured surfaces 

 have been so extensively applied in comparisons with the simul- 

 taneously measured total calories. So far as the total calories are 

 concerned, the general trend with both boys and girls is not unlike 

 that for the total heat referred to weight. So far as the calories per 

 square meter referred to area are concerned, the deviations from the 

 central line are too great to permit of any theorizing as to the existence 

 of a strict physiological relationship between heat production and 

 surface area. 



COMPARISON OF CALORIC OUTPUT PER SQUARE METER OF BODY-SURFACE WITH 



TOTAL BODY-WEIGHT. 



In the discussion of the charts dealing with body-surface thus far, 

 we have seen that with increasing body-surface there is an increased 

 total heat production, but when the calories per square meter of body- 

 surface are referred to the surface, the general trend shows an increase 

 in the metabolism to an area of 0.5 sq. m., and thereafter a definite 



FIG. 42. Basal heat production of boys per square meter of body-surface per 24 hours 



referred to body-weight. 

 Point inclosed in square signifies puberty established. 



decrease. These results throw absolutely no light upon the possi- 

 bility of a relationship between area and heat production, for the 

 surface may be simply another approximate expression of increasing 

 body-mass, and particularly the mass of organic protoplasmic tissue 



