A. R. Galloway 
273 
Remarks on the Pedigrees of Iris pigmentation. 
A. Family : 
This pedigree was constructed prior to April 1910, mainly on account of the 
large family of sixteen — from two blue-eyed parents II. 3, and II. 4. At that time, 
following Hurst's classification of simplex and duplex irides, I noted as having 
no anterior pigment those eyes which appeared to me to have none with focal 
illumination in good daylight. I have since found that many of these show the 
yellowish sheen of anterior pigmentation when rotated strongly upwards so that 
a foreshortened view of the pupil is obtained. This test was not applied either 
to the parents or children of this interesting family. It will be noted, however, 
that the mother II. 4 had a faint buff tint on the blue of the upper parts of each 
iris. 
It would serve no useful purpose, therefore, to look for the manifestation of 
Mendelian phenomena in this family, although the proportion of 14 blues without 
visible anterior pigment to 2 with tells against this mode of inheritance. I feel 
that the classification of eyes into "duplex" and "simplex" according to the pigmen- 
tation of the iris, is an impossible one, and must lead to inevitable confusion. 
It is interesting to note the inheritance, in the daughter III. 9, of the mother's 
brown spot of anterior pigment, and in the daughter III. 15, as a pupillary ring, 
of the mother's buff tinting*. 
In the eyes of I. 3, faint buff tinting was at first noted, and on a second 
examination deleted. This yellowish sheen would probably appear on upward 
rotation in good light in this case also. Three of her sisters, I. 4, 5, G, had anterior 
pigmentation well marked. 
The mating of III. 3, a pure blue, with III. 4, a uniform rich dark self- 
brown, is interesting, and has resulted in no iris that is, or can ever become, 
self-brown. Three of the children have well marked pupillary rings when the 
parents had none, and IV. 6 is almost an albino. In the mating of II. 5 with II. 6, 
unfortunately the husband could not be seen, but again from dark brown eyes and 
almost pure blues there have resulted three with pupillary rings. 
F. Family: 
The chief points of interest in this pedigree — the mating of two blues which 
would be classified as pure blues with no anterior pigment by any non-professional 
examiner — are : 
1. The occurrence of a son, II. 3, with brown irides with a complete coating 
of anterior pigment. 
* For examination and report on III. 15 I am indebted to Major F. M. Mangin, R.A.M.C., Specialist 
in Ophthalmology, Aldershot Command. 
Biometrika vm 35 
