E. SCPIUSTBR 
41 
measurement. Thus reckoned there are 959 men included in my tables. 29 of 
18 years of age, 330 of 19, 209 of 20, 137 of 21, 95 of 22, and 59 of 23 and over 
The average values for each measurement employed have been determined for 
each of these six groups and their standard deviations as a measure of variability. 
In addition a large number of correlation coefficients between pairs of measure- 
ments have been calculated for the five largest groups. 
Measurements and Test Applied. 
(1) Spot Pattern Test. This test was devised by Dr McDougall and included 
in our schedule at his suggestion ; he considers that it forms a measure of the 
power of concentration. Its object is to find how soon a simple pattern may be 
correctly reproduced. The pattern, of which a sample is shown below, is made by 
pricking holes in a square of cardboard. The holes lie in equidistant rows and 
columns, the distances between them being obtained by first plotting them at the 
Figure showing one of the patterns employed in the text. 
It can he used any way up. 
points of intersection of the lines on sectional paper. The number of rows and 
columns is limited to five so that the number of possible places for the spots is 
25. The first pattern attempted has nine spots placed irregularly in these positions. 
The cardboard square is placed in a wooden frame which brings it to the level of 
the eyes of the subject who sits before it, behind is placed a large instantaneous 
self-setting photographic shutter and behind that again a carefully shaded electric 
light. When the shutter is worked, the subject sees the pattern for a small 
fraction of a second as a number of bright spots arranged like a constellation. 
The procedure is for the operator to show the pattern once and then to read the 
simple directions. After this the pattern is shown again five times at intervals of 
about two seconds ; the subject is then required to attempt to map the spots on 
sectional paper with the same sized squares as that used in making the pattern. 
Areas are ruled off on the paper of the right size for the purpose. The first 
attempt is generally a failure, though one or two successes are recorded ; the 
pattern is then shown again five times and a fresh attempt is made, if this is also 
unsuccessful the procedure is again repeated, and so on till the map is correctly 
drawn, except that in order to save time no one was allowed more than ten 
attempts. 
Biometiika vin 6 
