IMDIV1IHTALS AXD MEASUKEMElNrrS COlNfiSIDEKED. 69 



Comparing with other characters dealt with in this volume, we note 

 that the metabolism off a group off mdividiuials is foom 2 to 3 times as 

 variable as their stature, (tabBe 8), but is not in any instance as vari- 

 able as their body-weight (table 11). The relative variability off total 

 heat-production is also, roughly speaking, firom 20 to 25 per cent 

 greater than body-surface area as measured by the Meeh formula 

 (table 50). This point is off particular interest because off the fact that 

 if heatrproduction were proportional to body-surf ace area, asmaintained 

 by many, the variability off these two measures should be the same. 

 To a fun consideration of t his matter we shall return in Chapter VI. 



These values are by no means as large as those which have been 

 found for the variation of weight of internal organs in man. For 

 example, Greenwood V a series shows coefficients of variation for the 

 weight of the spleen of 38.2 and 50.6 per cent in normal and hospital 

 populations. The same author finds a coefficient of variation of from 

 22.2 to 32.4 for the weight of the heart in hospital series and 17.7 in 

 normal series. For the weight of the kidneys the coefficients are 21.1 

 to 24.6 for hospital and 16.8 for normal subjects. For the weights of 

 the liver the constant is 20.8 to 21.1 for hospital series and 14.8 for 

 healthy series. 



Comparison of the relative variability of total heat-production 

 with that of another physiological measurement, pulse-rate, shows that 

 the two are roughly of the same order of magnitude. In the whole 

 series of men total heat-production shows a variation of 12.54*0.52 

 as compared with 10.99*0.48 for pulse-rate, a difference of +1.55 

 *0.71. In the whole series of women the comparable values are 

 11.50*0.55 for heat^roduction and 12.01*0.61 for pulse-rate, a 

 difference of 0.51 *0.82. Thus the two differences for total series 

 are opposite in sign, and neither can be looked upon as statistically 

 significant in comparison with its probable error. Unfortunately 

 pulse-rate is not available for all the individuals but this can hardly 

 affect the correctness of the conclusion. 



These comparisons with characters the variability of which is more 

 familiar to the general biologist and physiologist, win perhaps indicate 

 the relative magnitude of variation in total heat-production. The 

 individual constants will be extensively used in the analysis of the 

 various problems in the following chapters. 



4. RECAPnULATION. 



This chapter has had a threefold purpose. 



A. To describe the measurements dealt with and to give the 

 Symbols by which they are designated in the subsequent discussion. 



B. To give protocols of the actual measurements analyzed in 

 subsequent sections. These comprise 51 male and 43 female infants 



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