Porter — The Physical Basis of Precocity and Duliness. 163 
the High School at age twenty-two. 
In the higher grades, 
however, the number of girls over seventeen and of boys over 
_ sixteen years of age is too small to serve as material for our 
TABLE No. 1. 
eigen + by School ak of the 
eights of boys ag 
be PE TVS Vs 
ees ree eeudaeae dy ete 
roe ce peagese 
* 
Om em Om Oo: 
ee ay 
is 2 
= 
a 
Cre ONAIN Ome es 
_ 
o 
Baranoa 
ee 
“ee 
BRASS 
: al 2 : : 
peel ee oes OD We ie: me reOROhO: HR WH: 
ee a ee eas SE eee oes 
Cet ee eee oreo: 
were bee 
eee oben 
present needs. My conclu- 
sions are therefore limited to 
twelve years in the life of 
girls and eleven years in the 
life of boys. 
Within this period, chil- 
dren of the same age are 
grades. 
thirteen whose weight was 
recorded, 6 were in Grade I, 
and 6 in the High School, the 
remainder being distributed 
through the other grades, the 
greatest number (363) being 
in Grade IV. But here the 
number in the highest and 
lowest grades is again too 
small forour present purpose. 
For this reason, no number 
less than 20 has served as a 
basis for the calculations we 
are presently to consider. 
The distribution of the 
weights of boys aged nine 
by School Grades is shown 
in Table No. 1, compiled 
from the forms filled out in 
the schools by those who 
weighed the pupils. 
In this table the weight 
is expressed in pounds in 
the column on the left, and 
opposite each pound is placed 
the number of boys of that 
weight in each grade. 
