86 METABOLISM AND GROWTH FROM BIRTH TO PUBERTY. 



were changes in the personnel of the assistants from time to time, 

 as well as possibilities of difference in the depth of insertion of the 

 thermometer bulb, we may not look upon these observations as a 

 refined physiological study of changes in body temperature of children. 



It is to be regretted that a study of the diurnal rhythm of the rectal 

 temperature of children of various ages could not have been included 

 in the research, but this was impracticable. To use occasional obser- 

 vations of rectal temperature as a basis for determining the physio- 

 logical temperature of children is open to serious question, since the 

 well-known influences of activity, ingestion of food, and sleep make 

 such measurements liable to gross variability. When one considers 

 that the normal range in temperature is but 2 or 3 F., it will be seen 

 that if a study of the body temperature is to be made with strict 

 scientific accuracy, a much more sensitive measurement should be 

 used than that employed in this research. But as the measurements 

 were all made with the child inside a chamber, lying quietly on a 

 comfortable bed, we believe that although the method was admittedly 

 defective, the conditions were essentially comparable and the values 

 may legitimately be used for drawing conclusions. 



The rectal temperature was usually recorded, at least with the 

 younger children, just before and just after each respiration experiment. 

 Several hundred observations of the body temperature of these children 

 were thus obtained. It appeared unnecessary to give detailed publi- 

 cation of all these records, and we have therefore averaged the two 

 observations for each experiment and grouped them in table 22, accord- 

 ing to sex, as general averages for certain average ages. In these 

 averages the relatively few records of 100.5 F. or over have not been 

 included. The number of observations entering into each average is 

 also shown in the table. If measurements were made with but a 

 single subject for any particular age, the values were not included in 

 this comparison. From these average values an indication of the 

 general trend of the body temperature of children during the period 

 of growth may be obtained. 



The values for boys range from 97.1 F., the very low value for the 

 two boys averaging 5 years of age, to a maximum of 99.5 F. in the 

 group of six boys for If years. During the first month or two of life 

 the temperatures for boys are somewhat low, but with evidence of a 

 tendency to rise thereafter, the maximum continuing for approximately 

 two or three years. Subsequently the figures incline to run below 

 rather than above 99 F., and after 10 years all values are 98.8 F. 

 or under. Special attention has already been called to the extra- 

 ordinarily low value of 97.1 F. for the two boys 5 years of age, which 

 must not be looked upon as characteristic of that age. 



This table must not be considered as indicating the minimum tem- 

 peratures at these various ages. According to previous experimenting 



