GROWTH AND SENESCENCE. 



1013 



indicate abnormalities in growth due to undernutrition, foci of 

 infection, etc., conditions which it should be possible to correct. 

 The signs of old age may be detected in other ways than by 

 observations upon the rate of growth. Changes take place in 

 the composition of the tissues; these changes, at fii-st scarcely 

 noticeable, become gradually more obvious as old age advances. 



HEIGHT-WEIGHT TABLE FOR BOYS* 



Height, 

 inches. 



5 

 Yrs. Yr 



7 8 9 10 



Yrs. Yrs. Yrs. Yrs. 



120 

 123 

 127 

 131 

 136 

 139 

 143 

 145 



The bones become more brittle from an increase in their inorganic 

 salts, the cartilages become more rigid and calcareous, the crys- 

 talhne lens gradually loses its elasticit}^, the muscles lose their 

 vigor, the hairs their pigment, the nuclei of the nerve cells be- 

 come smaller, and so on. In every way there is increasing evi- 

 dence, as the years grow, that the metabolism of the living mat- 



* Prepared by Dr. Thomas D. Wood, "Cbild Health Organization," 

 New York. 



