30 American Statistical Association. 



ical labor. Greater height entails increased work on the 

 heart and on the skeletal muscles. In short, increased loss 

 of energN'goes hand in hand with increase in height. Hence 

 in the tall the necessity of a physical development which 

 shall be so much above the mean as to compensate .their 

 greater loss of energy. In growing children not only must 

 there be compensation for the expenditure of energy, but 

 there must be energy stored in the increase of tissue which 

 constitutes growth. 



If the greater demands of tall children are balanced by a 

 correspondingly greater income of energy, a normal equilib- 

 rium or 'Miealth" is preserved. It should be clearly recog- 

 nized that this equilibrium is unaffected by the absolute 

 height, and is dependent only on the relation between height 

 and the other physical dimensions. Consequently, health is 

 as possible in tall children as in those of normal height, 

 although less probable, for the chances against a compensa- 

 tory development of weight and other dimensions increase 

 very rapidly with the deviation of the height from the norm. 

 The absolute height of an individual is, therefore, of very 

 secondary interest from a practical point of view, because it 

 is not necessarily a state of ill health, whereas the develop- 

 ment of weight, girth of chest, etc. in proportion to height is 

 of supreme interest. The lack of proportion between height 

 and other physical dimensions is itself ill health. The tend- 

 ency of organisms to adapt ends to means is strong, and an 

 imperfect compensation may suffice for most demands. A 

 heart in which an hypertrophy of the left ventricle has par- 

 tially compensated an insufficiency of the mitral valve may 

 beat regularly enough for ordinary exertions, and yet fail 

 utterly when its possessor is forced to suddenly ascend a 

 height, or to make any other unusual exertion. So a tall 

 child may have a sufficient income of energy to meet the 

 demands of a wisely regulated life, and sink under the burden 

 of unusual tasks. 



