no 



THE HUMAN MOTOR 



MacAuliffe and Marie found, by a series of measurements, that 

 the Parisian is about 3 centimetres taller than the average 

 Frenchman, f 1 ) 



The relation ol height to age differs in the two sexes. At birth 

 boys measure 49'9 cms. and girls a little less, 49-2 cms., according 

 to the average ol determinations in Paris. The difference grows 

 wider with years. Until 12 ^ears old there is not more than 2-3 

 centimetres difference. Woman is full-grown at about 18 years 

 of age, but man continues growing and does not stop until be- 

 tween 25 and 30 years of age. 



The foregoing curves from results obtained by Quetelet ( 2 ) 

 give the relative variations of height in both sexes between 6 

 and 60 yeais of age (fig. 117). 



From fifty onwards the stature undergoes a reduction ; this is 

 senile decay, and reaches 25 cms. for man, 2'7 cms. for woman, at 

 about the age of 60. It affects tall people most, and they become 

 bent and shrunken. 



In addition to this natural evolution, it is recognised that 

 vertical pressure such as the carrying of weights, slightly reduces 

 the stature and the upright position, when it is continuous and 

 repeated, has the same result. On the contrary, however, a 

 lying or sitting position, such as forced immobility in bed. 

 increases the vertical development of the body. It seems as if 

 people who hold themselves very erect, notably soldiers, increase 

 their stature a little and conserve that increase. 



HUMAN STATURE. 



(*) Marie and MacAuliffe, Comptes Rend. Acad. Sc., 29th May, 1911. 

 ( 2 ) Quetelet, Physique Sociale, II, ch.ii., iii. ? and 1869 ; Anthropometrie, 

 1 87 1 . 



