100 METABOLISM AND GROWTH FROM BIRTH TO PUBERTY. 



cases out of the thirteen giving an increase. The pulse-rate also 

 shows a fall in all but three cases, but no one of these three was simul- 

 taneous with the rise in the metabolism. Unfortunately, the data for 

 the girls are somewhat meager as compared with those for the boys. 

 With four of the six girls the metabolism rose on the second day, but 

 with two of the girls the rise was insignificant. The pulse-rate almost 

 invariably fell slightly. Neither the boys nor the girls show a differ- 

 ence in the comparison of results due to age. The slight changes 

 noted between the two sexes must be considered primarily of a psycho- 

 logical and only secondarily of a metabolic nature. 



The values in table 24 thus demonstrate that the element of novelty 

 plays no appreciable role in the basal metabolism. This finding is in 

 full accord with the recent series of observations by Hendry, Carpenter, 

 and Emmes 1 on a group of medical students, and makes it seem all the 

 more probable that the small amount of preliminary training considered 

 absolutely essential for metabolism measurements may be reduced to a 

 minimum. Apparently, with complete muscular repose, the influence 

 on the pulse-rate of previous experience in the respiration chamber is, 

 with children, of minor significance. 



METABOLISM AS AFFECTED BY GROWTH. 

 GENERAL METHODS OF STUDY. 



An ideal study of the metabolism of children from birth to puberty 

 would be the continuous measurement of the same child at frequent 

 intervals throughout this period of life. All past experience has 

 shown that the physiological activities of a child can by no means be 

 represented by a straight line or by a regular curve function, for there 

 are gross irregularities which are inexplicably and inherently a part 

 of physiological life. Accordingly it is necessary to base deductions 

 not upon the analysis of the metabolism of one child alone, but upon 

 the metabolism of several children. Hence we felt it our duty to 

 obtain measurements for a number of boys and girls during as long a 

 period of life as they were available. The children of wet-nurses 

 could be more or less controlled from birth, but as each year passed 

 they became more widely scattered, and consequently it was increas- 

 ingly difficult to secure them for observation. But even under these 

 conditions we were able to hold and to study a representative number 

 of these children. In all, studies were made with 23 children over 

 varying periods of time. In no instance, however, could we approx- 

 imate the ideal of intermittent measurements from birth to puberty, 

 for after three or four years of observation it became impossible to 

 keep in touch with the children. 



1 Hendry, Carpenter, and Emmes, Boston Med. and Surg. Journ., 1919, 181, pp. 285, 334, and 

 368. 



