NORMAI PKOCESSES OF ENERGY METABOLISM 635 



by the latter authors. According to Meeh's formula the basal heat pro- 

 duction of the newborn was 23.7 calories per square meter per hour. 



Benedict and Talbot interpret their results on all their infants be- 

 tween birth and one week of age as showing no relation between body 

 surface and metabolism. Yet when two extreme groups like those men- 

 tioned on pages 632 and 633 are selected from their results, it is found 

 that the average metabolism per unit of weight differs 12.5 per cent, while 

 on the basis of surface area (Meeh's formula), the same groups show a 

 difference of less than 3 per cent, namely 24.1 and 23.4 calories per square 

 meter per hour. 



The basal metabolism of the newborn above 12 hours of age while, 

 sleeping quietly at a comfortable temperature is in the neighborhood of 

 23 or 24 calories per square meter of surface, in contrast with that of the 

 adult which is in the neighborhood of 32 or 33 calories. In other words, 

 the metabolism of the newborn is nearly one-third less than that of the 

 adult. On the same basis, the basal metabolism of the 31 newborn babies 

 less than 12 hours of age in Benedict and Talbot's series is about 20 

 calories per square meter per hour or quite 40 per cent less than that of 

 the adult. Singularly enough this same level of metabolism may be 

 reached by the adult after twenty days of fasting. 



4. Influence of Sex on Basal Metabolism of Infants. From the sec- 

 tions immediately preceding, it is already evident that sex at this early age 

 exercises little, if any, specific influence. Further examination confirms 

 this impression. Thus the group of 31 infants under 12 hours of age in the 

 Boston series includes 17 males and 14 females. The average weight of 

 the males is 3.76 kilos and they have an average metabolism per kilo and 

 hour of 1.53 calories. The average weight of the females is 3.29 kilos and 

 they have an average metabolism per kilo and hour of 1.61 calories. The 

 metabolism of the larger body is slightly less as before. The two groups, 

 however, have exactly the same metabolism per unit of surface. 



Carrying the comparison to older groups, we find the same is true of 

 all infants two days of age. There are seven boys and seven girls of this 

 age in the Boston series. The average metabolism of the boys is 1.85 

 calories per kilogram and hour, while that of the girls is 1.87 calories. 

 The average metabolism per unit of surface (Meeh) is 23.5 calories for 

 the boys and 23.2 calories for the girls. Using the DuBois height-weight 

 formula and calculating the surface, the average for the boys is 30.7 calories 

 and for the girls 30.4 calories. The mean percentage deviation from the 

 average is slightly less for both groups on the basis of the Meeh formula 

 than it is on the basis of weight or on the basis of the surface as estimated 

 by the DuBois formula (Table 29). 



Going on to infants 4 to 5 days of age, in the same series, we find the 

 average weight of the boys is 3.34 kilos, that of the girls 3.83. The basal 

 heat production per kilo and hour of the former is 1.88; that of the latter 



