174 METABOLISM AND GROWTH FROM BIRTH TO PUBERTY. 



The chief importance of the curve in figure 45 is to show the pro- 

 nounced metabolism of early youth up to 1 or 2 years. As we have 

 already stated, there can be no great preponderance in the proportion 

 of active protoplasmic tissue in a child 1 or 2 years of age. In all 

 probability we have here a specifically high metabolism at this age, 

 which is certainly worthy of further investigation, with, if possible, 

 a minimizing or elimination of the disturbing factor of stimulus 

 from food (see page 30). 



Cals. 

 1350 



CALORIES PER SQ. M. REFERRED TO AGE. 



BOYS. 



675 



600 



Yrs, .1 



10 11 12 13 14 15 16 



FIG. 45. Basal heat production of boys per square meter of body-surface per 



24 hours referred to age. 

 Point inclosed in square signifies puberty established. 



For the studies on boys made by earlier investigators, a plot is 

 made in figure 46 and our smoothed curve included in the chart. The 

 usual experience is here repeated, namely, that the earlier values, 

 with but one exception, lie above the smoothed curve; in most in- 

 stances, the points are very much above the line. Especially worthy 

 of note are the high values recorded by Du Bois between the ages of 

 12 and 14 years. These have brought once more into active discussion 

 the influence of the prepubertal stage upon basal metabolism. 



Our observations on girls are all plotted in figure 47, upon which 

 is laid a somewhat complicated smoothed curve, this being the result 

 of an attempt to represent the general trend in spite of the great 

 irregularity and wide dispersion of individual points. The most clearly 

 established feature of the curve is the prevalence of low values at the 

 early ages, rapidly ascending until about 1 or 2 years, with a tendency 

 towards a subsequent decrease. With two of the girls, puberty was 

 definitely established and with one other it was beginning. Of the 



