NORMAL PEOCESSES OF ENERGY METABOLISM 613 



TABLE 22 



total heat production. His chart in terms of calories per hour per square 

 meter of body surface appears below. In considering the causes of the al- 

 tered rate of heat production, one must bear in mind first the differences 

 in body form which themselves affect the relationship of body surface to 

 body weight ; secondly, the specific influence of different organs which not 



20 



10 



YEARS 2 



6 8 10 12 14 16 18 20 22. 



Fig. 35. Variations of basal metabolism with age: Calories per hour per square 

 meter of body surface M'eeh's formula. Dash line shows average for males, dotted 

 line for females. After DuBois. 



only bear different relations as regards size, to the body as a whole, but 

 probably in some instances also have quite a different coefficient of activity. 

 Thus, in early life the liver and thyroid, especially, both organs of high 

 metabolic activity, are perceptibly larger in the relative sense than in 

 the adult life, and may be expected to play a larger part in the total chem- 

 ical activity of the body. This may, to a large degree, account for the 



