488 



AN AMERICA X TEXT-BOOK OE PHYSIOLOGY 



height occurs, while from the accumulation of fat the weight usually rises 

 markedly up to the fiftieth or the sixtieth year. One of the most interesting 

 results revealed by statistics is the relative growth of the two sexes. From 

 birth up to about the age of ten or twelve, boys show a slight and increasing 

 preponderance over girls, but the two curves are nearly parallel. The prepu- 

 bertal acceleration of growth in girls, however, precedes that of boys, and is 

 even accompanied by some check in the male growth, with the result that 

 between the ages of twelve and fifteen girls are actually heavier and taller 

 than boys. This fact, first pointed out in 1872 by Bowditch 1 from observa- 



Fig. 229.— Diagram showing increase of stature and weight of both sexes, as determined by the Anthropo- 

 metric ( lommittee of the British Association. 2 



tions on several thousand Boston school children, has been abundantly con- 

 tinued by Pagliani in Italy, Key in Sweden, Schmidt in Germany, Porter in 

 St. Louis, and others. At about fifteen years boys again take the lead and 

 maintain it throughout life. Boys grow most rapidly at sixteen, girls at thir- 

 teen or fourteen, years of age; the former attain their adult stature approxi- 

 mately at twenty-three to twenty-five, the latter at twenty to twenty-one years. 

 The details of growth and the actual measurements vary considerably with 

 race ; thus the supremacy of the American girl over her brother appears to be 

 less marked and to cover a shorter period than that of the English, German, 

 Swedish, or Italian girl. Children of well-to-do families are superior to 



1 II. P. Bowditch : Eighth Annual Report of the State Board of Health of Massachusetts, 1877. 



2 Roberts: Manual of Anthropometry, 1878. 



