306 Trans. Acad. Sci. of St. Louis. 
pubertal acceleration. 2. The weight of girls is much more 
influenced by the material prosperity or social status of 
parents during and immediately after the period of pre- 
pubertal acceleration than in the earlier years of growth. 
The proportion of children of the more prosperous class in 
the public schools is not the same in all grades. In the higher 
grades, containing the older children, the number from pros- 
perous families is relatively larger, the children of the poor 
having in many instances been compelled to leave school in 
order to earn money. Some idea of the extent of this change 
may be gained from Table No. 14, in which the per cent. of 
daughters of professional men and merchants and daughters 
of manual tradesmen is given at each age and school grade. 
