DISCUSSION OF RESULTS. 



149 



Table 33. — Average weights of American 

 infants (Holt). 



average weight of infants given by Holt. 1 (See table 33.) For example, 

 if the infant weighed 0.5 kilogram more than the average weight at 

 birth and we wished to know what it would have weighed at 5 months 

 had it developed in the usual way, we added 0.5 kilogram to 6.82 

 kilograms (the average weight for this age as recorded by Holt) and 

 considered 7.32 kilograms the weight that the infant would have weighed 

 had it developed normally. The same procedure was followed if the 

 infant was under weight. 



It is clear that relatively few of 

 the infants included in our study can 

 be considered of normal weight, that 

 is, the average weight of healthy 

 infants, as only 8 out of the 37 

 reported are equal to or exceed the 

 normal weight; one of the infants, 

 H. T., is considerably above the 

 normal weight. It is understood, 

 then, that we are considering for 

 the most part infants that are under weight. Certain of these were 

 in the subnormal temperature stage of infantile atrophy; others were 

 in the repair stage and with normal temperature. 



The term " infantile atrophy" is applied to an emaciated infant with 

 such severe indigestion that it is unable to digest weak mixtures of 

 cow's milk, with no gain in weight, and with a subnormal body-tem- 

 perature. The convalescent stage of infantile atrophy is that in which 

 the same infant subsequently begins to digest its food and to gain 

 weight, and has a normal temperature. Under-weight infants are 

 those who are 0.5 kilogram or more below the average weight for 

 their respective ages but whose digestion is not so severely deranged 

 as those with infantile atrophy. This group includes all infants not 

 classified as normal, or with infantile atrophy, or in the convalescent 

 stage of infantile atrophy. 



RELATIONSHIP BETWEEN BODY-WEIGHT AND METABOLISM. 



One of the two factors commonly referred to as exercising a most 

 pronounced influence upon the total metabolism is the body-weight. 

 Charts have therefore been prepared in which comparisons have been 

 made between the body-weights of our infants and the heat-production. 



'We recognize that there is no absolutely definite normal weight that can be established for all 

 infants. The charts of growth given by the various authorities are all very similar, their differ- 

 ences being explained by the fact that they often represent infants of different nationalities or of 

 different social and hygienic surroundings. Since the charts usually represent average and not 

 normal infants, it is very difficult to apply the test of normal or abnormal weight to any given 

 infant. Therefore, in comparing the infants used in this investigation, both the average and the 

 estimated weights will be considered. Hereafter we shall use the term "normal weight" as 

 meaning the average weight. The average weights of American infants are given in table 33, 

 which is taken from Holt (toe. cit., p. 17), who made it up from the records of 100 healthy nursing 

 infants and the incomplete weight charts of about 300 other infants. 



