J. F. Tocher 
179 
in the case of blue eyes, the interlocal or segregation constants (s— 1) being 
5'02 and 4'12 respectively (see also Diagrams VI. and XV.). The odds against 
an even distribution of persons belonging to this class is thus enormously great, 
as also are the odds against persons of the faii'-haired class being evenly dis- 
tributed (see Diagrams I. and X.). The difference in the segregation of the boys 
and girls is marked. Medium hair and dark hair are approximately equal to fair 
hair (J') in their divergence from uniformity of distribution (Diagrams III., IV., 
XII. and XIII.), and then follow medium and dark eyes (Diagrams VIII., IX., 
XVII. and XVIII.), and with slightly less segregation still, light eyes (Diagrams 
VII. and XVI.), and jet black hair (Diagrams V. and XIV.). Finally, in the 
case of red hair the interlocal constant shows persons belonging to this class to 
be the most evenly distributed one throughout the country (Diagrams II. and 
XL). In no case, however, can the exact probability of an individual belonging 
to any particular class be predicted with accuracy, just on account of the uneven 
nature of the distribution of persons belonging to the class. It falls finally to be 
noted here that the differences for each class have been considered collectively, 
without reference as to where they occur geographically or as to whether the 
differences for boys and girls occur together in the same place. This point is 
specially dealt with in another section, where a measure is given of the agreement 
of the sexes in colour characters. 
The most striking result in this section is that bearing on red hair. Its 
distribution is so markedly different from the rest of the classes as to attract 
attention. The occurrence of red hair in Scotland either (a) is independent of 
race, or {^) is one of the effects of blending of races — perhaps widely divergent 
races, or (7) is an abnormal condition in hair colour and deserves the attention 
of the physiologist and pathologist. 
(9) Pecidiarities in the Distribution of Colour in Scotland. 
I. General. An examination of Table XXIX. will show how far the distri- 
bution for boys and girls differ, and also what excesses for hair colour and eye 
colour occur together. It should be noted that this does not necessarily mean 
that a particular combination (e.g. fair hair and blue eyes) is in excess. This 
can be accurately determined only by comparing the excess frequencies of the 
particular combinations found in the localities under consideration with the pro- 
portional frequencies of the same combinations in the general population. The 
statistical labour involved in such an analysis would be very great and could 
not be attempted by the writer until the present analysis had been completed. 
Besides, no funds were available to defray the considerable additional expense 
which would have been incurred in providing for clerical assistance in tabling 
the combinations and otherwise completing the statistical analysis. Thus, the 
results of the present investigation are those flowing from individual classes and 
only indirectly from combinations. 
