154 METABOLISM AND GROWTH FROM BIRTH TO PUBERTY. 



the rise in the sketched curve is perfectly justifiable. The maximum 

 occurs at about 7 or 8 kg., this approximating the average weight for 

 children of one year. Thence the curve decreases with a reasonable 

 degree of regularity. Not until 24 kg. and over is reached do the 

 points lie sufficiently close to the central line to give a clear idea of 

 physiological regularity in the metabolism per kilogram of body- 

 weight referred to the total weight. 



Cals. 



CALORIES PER KILO. REFERRED TO WEIGHT. 



BOYS. 



FIG. 35. Basal heat production of boys per kilogram of body-weight per 24 hours 



referred to weight. 

 Point inclosed in square signifies puberty established. 



The suggestion of sexual differentiation between boys and girls, 

 even at the early ages, noted in the calories per kilogram at the age 

 of one year, makes it desirable to consider by itself the metabolism 

 per kilogram of the girls at different weights. These values are plotted 

 on the chart in figure 36, together with our smoothed curve indicating 

 the general trend of metabolism. The most pronounced feature of 

 this chart is the wide scatter of the individual points from the smoothed 

 curve, this being even more evident for the girls than for the boys. 

 Still, it is reasonably clear that the general trend shows a rise between 

 3 and 8 kg., where the maximum is found, with a clearly defined 

 decrease thereafter to about 26 kg. Subsequent to that point the 

 line appears to be reasonably level, but the number of points available 

 beyond 30 kg. is so few as hardly to justify discussion. Up to 18 kg. 

 there is such a wide dispersion of points about the smoothed curve 

 that no conclusion may be drawn regarding a physiological law, even 



