PHYSIOLOGICAL NEEDS VS. SUPPLY. 117 



essentially constant, being 114 for the second day and 116 for the three 

 following days. At the end of the week there was a distinct increase, 

 the pulse for the sixth, seventh, and eighth days averaging 122, 119, and 

 126, respectively. 



While we would again emphasize the fact that these pulse-rate obser- 

 vations were wholly incidental to the studies of the metabolism, yet 

 our previous experience has led us to be so cautious in our selection of 

 average values and of minimum values that we may say with confidence 

 that these figures represent the average minimum values for the pulse- 

 rate of a considerable number of new-born infants during the first 8 

 days of life. The fact that the low pulse-rate for the first day is coinci- 

 dental with a low average body-temperature and heat-production is only 

 what would naturally be expected in view of the results obtained in 

 our previous researches and bears out the theory that the best indices 

 of internal muscular activity or internal cellular activity are the pulse- 

 rate and the body-temperature. Under normal conditions fluctua- 

 tions in the body-temperature are not so great as to define sharply the 

 relationship between the body-temperature and the metabolism, except 

 when there is a febrile temperature. With the supercooling of these 

 infants, however, the low pulse-rate and its attendant low metabolism 

 and low temperature are strikingly in accord. 



PHYSIOLOGICAL NEEDS VS. SUPPLY. 



As a result of this study of the metabolism of the new-born infant, 

 certain fundamental values may be considered as definitely established, 

 namely, the basal energy requirements of the new-born infant for the 

 5 days following the first 24 hours of life. Our calculations of the mini- 

 mum metabolism, upon which we base our discussion almost exclusively, 

 show a remarkable degree of uniformity in these values. From the 

 tables recording the minimum and maximum metabolism, data may be 

 obtained for also computing the approximate energy requirements of the 

 new-born child during a day of varied activity. The maximum values 

 have been shown to vary enormously in individual cases, but the results 

 of the whole series average 65 per cent above the basal metabolism. 1 



In estimating such requirements we are dealing only with the problem 

 of maintenance, assuming that during the first week we may disregard 

 the requirements for actual growth (at least for the purposes of dis- 

 cussion) . Hence the primal consideration may be stated to be : Is the 

 normal food-supply of the new-born infant during the first week suffi- 

 cient for maintenance, disregarding any needs for growth? As the 

 evidence that we have accumulated may have a certain directly prac- 

 tical value in this connection, the energy output and its quantitative 

 relations to the energy intake may very properly be considered. Prac- 

 tical experience, particularly in regard to the noticeable loss in weight 



! See p. 112. 



