A. R. Galloway 
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4. The pupillary rings of I. 1 are repeated in both the children. 
5. Yellow staining on the blue irides of I. 2 occurs only in the upper and inner 
regions. 
E. Family: 
1. The blue eyes and reddish hair of I. 2 are probably connected with the 
appearance of an incomplete albino II. 2. 
2. The examination of this patient II. 2, as detailed, combined with the 
microscopic examination of G. C.'s eye, has convinced me that it is quite impossible 
to say when any living person's blue eye is free from anterior iris pigment, and 
has led me to doubt that this ever truly occurs. 
Conclusions. 
1. The human iris cannot be held to consist merely of an anterior and 
a posterior surface, each, in certain eyes, exhibiting its own kind of pigment. 
2. The stroma may contain pigment cells more especially in its deeper parts 
and granular pigment towards the anterior surface. 
S. Pure blue, or so-called "simplex" eyes, which to any outward examination 
appear free from anterior pigmentation, may show stroma pigment cells, and 
anterior granular pigmentation when examined microscopically. 
4. Hence the classification of "duplex" and "simplex" eyes is erroneous, 
and there is no discontinuity or Mendelian inheritance between them. 
Pedigrees of Iris Pigmentation. 
All eyes that have been seen have been examined by myself, except III. 15, 
Fig. A. 
The symbols used have been devised to indicate the main types of iris 
pigmentation occurring in the following pedigrees, but, as already mentioned, 
these varieties are so numerous that several grades of colouration must be included 
under some of the symbols. 
The aim of these pedigrees is to indicate how complex is the problem of 
heredity of eye colour, when we pass from a mere rough appreciation of the extent 
of pigmentation, as provided by the ordinary verbal descriptions, to an analysis of 
its distribution throughout the iris. 
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