178 Pigmentation Survey of School Chikh-en in Scotland 
that the coi'relation between age and hair colour is quite appreciable. On the 
assumption that the rate of change of hair colour and e3'e colour with age is 
not likely to vary appreciably in passing from one district to another, the author 
determined the probable distribution of the colour of the adult population of 
Scotland. The result was published in the same memoir*. Using the result 
together with the percentage results for the whole of Scotland for boys and girls 
as found from the present data, the following table (Table XXVIII.), constructed 
as a probability table, gives the chance of a person of Scottish nationality possessing 
any one of the following characteristics : — ■ 
TABLE XXVIII. 
TJie Probability of the Person belonging to any one of the following 
Colour Glasses is 
Boys 
Girls 
Colour 
Adult 
Population 
Scotland 
Generally 
Kange in 
Counties 
Scotland 
Generally 
Range in 
Counties 
From 
To 
From 
To 
Hair : 
Fair 
Red 
Medium 
Dark \ 
Jet Blacks ■•• 
■115 
•042 
•559 
•284 
•250 
•055 
•433 
•250 
•013 
•221 
•046 
•373 
•187 
•008 
•314 
•069 
•495 
•308 
•024 
•274 
•051 
•409 
•254 
•012 
•243 
•041 
•356 
•194 
•002 
•344 
•068 
•474 
•291 
•026 
Blue ) 
Lightf 
Medium 
Dark 
•278 
•459 
•263 
•147 
•303 
•327 
•223 
•103 
•227 
•279 
•174 
•259 
•337 
•344 
•244 
•148 
•303 
•321 
•228 
•118 
•241 
•266 
•159 
•252 
•348 
•358 
•263 
With regard to the juvenile population, the above table shows that one can 
hardly say any particular eye colour is typical of Scotland. There is a bias in 
favour of light and medium eyes. Brown hair is the most likely colour for a 
child to possess. Fair and dark are equally likely hair colours in the juvenile 
population. Medium eyes and brown or medium hair are niore typical of the 
adult population. 
Summarising the results of this section, it has been found possible to classify 
the degrees of segregation of the colour classes — a segregation already proved, 
although its amount was not revealed in any one case in considering the individual 
differences. It has now been shown that segregation of certain classes from others 
exists. The greatest segregation from others (or congregation as a class) is shown 
* Tocher: Biometrika, Vol, v. pp. 339—341. 
