A. M. Carr Saunders 
371 
only. Although many correlations were worked out and various points investigated 
by Tocher from his data, he did not use his material to throw light on this point. 
The Scottish data are more numerous than those from Birmingham, and the popu- 
lation more heterogeneous. But the environmental conditions are by no means the 
same, and moreover the population is a selected one. Therefore any positive 
results from such data, though interesting, would be far from conclusive, and 
would demand further investigation of the subject. 
Birmingham Data. Height and Pigmentation. The method of pigmentation 
classification used at Birmingham has already been described. The height was 
taken to the nearest millimetre. This latter fact is of importance in calculating 
the means. In order to form a table the numbers of each hair colour group were 
classed into groups of two centimetres each. Now, owing to the fact that the 
height is taken to the nearest millimetre, the middle point of the group 
150 — 152 centimetres will not be 151 but 150 - 95. The data were first treated 
by calculating the means and probable error for the total number of boys and 
girls and thus for each of the six hair colour groups. The result is given in the 
following table. 
TABLE XII. (See Tables XVII and XVIII, pp. 380—381.) 
Hair Colour and Height. 
Mean Height in Centimetres. 
Hair Colour 
Boys. Age 13 
Girls. Age 13 
Red 
Fair 
Light Brown 
Medium Brown 
Dark Brown 
Black 
142-86+ -64 
142-47+ -28 
142-39+ -22 
142- 41 + -19 
143- 69+ -21 
142-69 ± -93 
144-15+ -51 
144-72+ -34 
143- 71 + -24 
144- 69+ -19 
145- 41 + -20 
144-56 ± -60 
Genera] Mean 
142-80± -10 
144-67 ±-12 
It is there seen that at this age girls are substantially taller than boys, i.e. by 
about two centimetres. When we look at the means of the hair colour groups, it 
is at once evident that none of them are going to show any marked deviation from 
the general mean. There are, however, some cases which demand closer attention ; 
these are the dark brown hair groups in both cases, and the light brown hair- 
group in the case of girls. In order to show this more clearly two figures have 
been constructed — one for the boys and the other for the girls. 
The method adopted in both these cases is the same. A straight line shows 
the mean of the whole number of boys or girls as the case may be. The means of 
the various hair colour groups have been marked and joined together. Two other 
lines have been introduced and tabled as indicating twice the probable error. The 
47—2 
