176 Pigmentation Surveij of School Children in Scotland 
h and s are interlocal constants. This test of the degree of homogeneity of a class 
or character in a population scattered over a wide area has already been" applied 
by the writer, the constants for both measurable and non-measurable characters 
being determined*. If then a population is non-segregated with respect to any 
class (that is, if persons belonging to the class are well distributed over the 
country) the interlocal constants h and (s— 1) will be both equal to zero within 
the limits of their probable errors, and the segregation of a class will increase as 
these constants become greater and greater. 
The following table (Table XXVI.) gives the values of the interlocal constants 
for both the boy and girl populations, the distributions considered being those 
of the relative local differences arrived at from the county data — that is, with 
the county as the unit of area. Table XXVII. is one in which the classes are 
arranged in the order of the significance from lesser to greater segregation. 
II. Significance of the Constants. These results show how decided the devia- 
tions are from purely uniform distributions of the class populations. It is seen 
that the blue-eyed class and the fair-haired class are both highly separated geo- 
graphically from the general population. The separation is greater in the case of 
fair-haired girls than in the boys of the same class. The deviation from a random 
distribution for boys and girls is of the same order in the other colour classes. 
TABLE XXVI. 
Interlocal Constants. Colour Segregation. 
(This table shows that a grouping of children of the same class occurs no matter what class 
is selected. The figures show the relative extent of the segregation of the classes.) 
A = mean of the series of relative local differences, boys or girls, for each colour class. 
s= standard deviation of the series of relative local differences, boys or girls, for each colour 
class. 
s„i = standard deviation, as above (boys). 
S/= standard deviation, as above (girls). 
Colour 
Boys 
Girls 
h 
s 
-1 
-1) 
h 
(s-1) 
s-1 
Fair Hair 
•45 
2-75 
34 
•12 
1^14 
5-U 
63^77 
-2 39 
Red Hair 
•18 
•69 
8 
•56 
•09 
•56 
6^95 
•13 
Medium Hair ... 
- -57 
2^82 
34 
86 
- -81 
2^90 
35-98 
- -09 
Dark Hair 
- -04 
2-24 
27 
•79 
- ^39 
2^95 
36 -60 
- -71 
Jet Black Hair ... 
•20 
1^36 
16 
87 
•32 
r93 
23^95 
- ^57 
Blue Eyes 
ri7 
5^02 
62 
28 
1^02 
4^12 
51 ^12 
•90 
Light Eyes 
- •OQ 
1-78 
22 
08 
•13 
1^85 
22^95 
- ^07 
Medium Eyes ... 
- -bl 
2^09 
25 
93 
- ^59 
2^15 
26^68 
- ^06 
Dark Eyes 
- -33 
2-11 
26 
18 
- ^35 
1-87 
23^20 
•24 
* Biometrika, Vol. v. pp. 323—327. 
