A. M. Carr Saunders 
363 
A and B are correlated and A and C are correlated, there must be a correlation of 
over *75 between A and B, and between A and C in order that B and C should be 
necessarily correlated. This table, however, does show a very similar result to 
the preceding table; and we do not find that any particular eye colour is asso- 
ciated with a greater or less average number of diseases; nor do we find, if we 
divide the classes of eye into light and dark, that there is any significant 
difference between them. In one case it might appear at first sight that there 
was some significant difference. The average number of diseases to both dark 
eyed boys and girls aged 3 — 7 falls somewhat below the general average. Calcu- 
lations were made to test for random sampling according to the method given by 
Elderton*. P was calculated in each case. For the boys aged 3 — 7, P worked 
out at - 33 and for the girls at '37, or in other words a less regular sample would 
occur more than 30 times in a hundred chances. There is, therefore, no im- 
portance whatsoever to be attributed to the drop in the average for the younger 
dark eyed boys and girls. 
TABLE VII. 
Incidence of Disease in Hair Colour Groups. Percentages. 
Boys and Girls. Age 13. 
Hair Colour 
Measles 
Whooping 
Cough 
Scarlet 
Fever 
DlPnTHERIA 
Mumps 
Chicken Pox 
Boys 
Girls 
Boys 
Girls 
Boys 
Girls 
Boys 
Girls 
Boys 
Girls 
Boys 
Girls 
Red 
79-0 
87-8 
38-7 
40-5 
17-7 
9-5 
1-6 
4-0 
27-6 
28-4 
37-1 
29-7 
Fair 
73-1 
87-4 
31-7 
44-4 
14-0 
16-2 
2-8 
5-5 
20-2 
21-1 
30-1 
29-6 
Light Brown 
71-9 
86-0 
34-2 
44-7 
14-5 
21-5 
3-2 
4-4 
19-8 
26-9 
27-9 
35-7 
Medium Brown 
77-6 
85-8 
39-9 
44-9 
17-4 
19-7 
4-7 
5-2 
20-9 
22-9 
28-4 
38-8 
Dark Brown 
75-5 
84-5 
37-8 
44-2 
17-7 
17-4 
4-2 
4-5 
23-3 
22-3 
27-2 
38-8 
Black 
79-5 
84-8 
52-0 
47-9 
22-6 
19-6 
o-o 
2 "2 
22-6 
13-1 
48-4 
43-5 
TABLE VIII. 
Incidence of Disease in Eye Colour Groups. Percentages. 
Boys and Girls. Age 13. 
Eye 
Colour 
Measles 
Whooping 
Cough 
Scarlet „ 
Fever Diphtheria 
Mumps 
Chicken Pox 
Boys 
Girls 
Boys 
Girls 
Boys 
Girls 
Boys 
Girls 
Boys 
Girls 
Boys 
Girls 
Blue ... 
Light... 
Neutral 
Dark ... 
73 7 
75-2 
73-5 
77-9 
85-6 
85-9 
85-9 
84-3 
36-7 
36-8 
36-4 
38-3 
41-3 
45-9 
44- 7 
45- 0 
15-6 
15-0 
17-5 
17-5 
22 - 2 
18-6 
18-6 
15-8 
4-9 
2-5 
4-4 
4-2 
3- 1 
6-9 
4- 6 
37 
19-5 
18-3 
25-0 
22-5 
21- 3 
22- 3 
27-5 
21-4 
25- 8 
30-4 
26- 7 
30-7 
35-7 
32-8 
35-9 
39-4 
* Biometrila, Vol. i. p. 155. 
46—2 
