828 PROCEEDINGS OF SECTION J. 
Ethnologie. In these papers the material was the total 
number of observations, irrespective of social conditions of 
parents. Let me take an example from Table 2 (see 
Chart K.). ‘The physical basis for precocity and dul- 
ness’? will illustrate the result of the inquiry. Pupils 
aged 11 are found in grades 1, 2, 3, 4, 5, and 6 of 
the St. Louis public schools, as the following table 
shows. Of the total number, 59 were in the lowest 
grade, the first; 311 in the second, &c. The number 
opposite the grade indicates the number of boys found in 
that grade. May I now ask you to look at the figures in 
the third column—these show the average weight of the 
boys in each class. You will notice that the boys in the 
first grade weigh less than the boys in the second; and 
these, again, are lighter than the boys in the higher grades. 
This shows that when you compare boys of the same age in 
sufficiently large numbers, you find that their mental ability 
is in direct proportion to their weight. 
Two years ago Dr. Christopher directed an examination 
of about 7000 children in Chicago. No expenditure of 
time, skill, and money was spared to make this the most 
thorough investigation of its kind ever made. He came to 
the same result as Dr. Porter, that average height and 
weight of school children decide their standing in school- 
work. (See Report of Board of Education of Chicago, 
1899.) 
Both these investigations show that the average dull 
child is shorter and lighter than the average bright child. 
They indicate that superior physical qualities are associated 
with superior_mental ability. 
Diagram M.—WLet me show you.a chart of Dr. Chris- 
topher. It shows the average number of physical abnor- 
malities of children below grade (that is, dull pupils), 
in pupils above grade, and in pupils of the John Worthy 
School. The school just mentioned is associated with a 
penetentiary, and contains young criminals, and also some 
homeless children who have shown no criminal tendencies. 
You will notice that the bright pupil has fewest physical 
irregularities of growth (line A), the dull pupils score 
slightly higher (line B), while the criminal boys are leading 
by a long way (line (). These lines indicate that the 
normal boy is likely to be the best boy morally. 
I have tried to show that normal growth is a very im- 
portant factor in the developing of the young, affecting 
their mental as well as their physical standing. 
