D. Macdonald 
33 
the less recuperative power it has and the less resistance is offered in the diseases 
here considered. 
(5) Special Gases. 
1. The incidence of nephritis in the various pigmentation types in scarlet 
fever. 
The possible connection between the pigmentation of the hair and eyes and the 
skin has already been considered. The type of skin, as one of the chief excretory 
systems in the body, might be expected to have an effect on the incidence of 
nephritis. In 1295 cases of scarlet fever in Ruchill Hospital 32 or 2 - 5°/ 0 suffered 
from true scarlatinal nephritis. In Table XVIII the percentages of those occurring 
in the various pigmentation types are given. The evidence is not very conclusive, 
but here again the darker type seems to offer more resistance. 
TABLE XVIII. Showing the Number of Cases and the Percentage 
developing Nephritis in the vai-ious Hair and Eye Colours in Scarlet 
Fever. 
(i) Hair Colour. 
Black 
Dark 
Medium 
Fair 
Eed 
Number of cases 
Percentage with nephritis 
8 
o-o 
214 
1-9 
749 
2-7 
251 
2-0 
73 
4-1 
(ii) Eye Colour. 
Dark 
Medium 
Light 
Blue 
Number of cases 
213 
833 
187 
62 
Percentage with nephritis 
2 3 
2'3 
32 
3 2 
2. The incidence of paralysis and the necessity for tracheotomy in diphtheria. 
The possible association between the ectoderm and pigmentation has already 
been mentioned. The peripheral nerves being ectodermal in origin, it was thought 
that some relationship might be found between the incidence of paralysis in diph- 
theria and the pigmentation of the hair and eyes. The evidence again is not very 
conclusive. In Table XIX the percentage of cases with subsequent paralysis, 
chiefly palatal, and the percentage of cases requiring tracheotomy in 535 children 
suffering from diphtheria have been tabulated with reference to the colour of their 
hair and eyes. The figures bear out what has already been said with regard to the 
severity of the disease, the dark and medium types being less severely attacked ; 
exceptions to this are found in the high percentage of cases of paralysis in dark- 
haired and in dark-haired dark-eyed children, and in the low percentage of cases of 
paralysis in blue-eyed children. 
Biometrika via 5 
