NOTES ON THE PIGMENTATION OF THE 
HUMAN IRIS. 
By A. RUDOLF GALLOWAY, M.B., CM, M.A, Aberdeen. 
CONTENTS. 
PAGE 
"On the Inheritance of Eye-Colour in Man," by C. C. Hurst .... 267 
His conclusions .............. 267 
Anterior pigmentation of blue and grey eyes 268 
Numerous types of Iris pigmentation 268 
Observations differing from Hurst's 268 
Layers and zones of the Iris 269 
G. C.'s Iris 269 
Microscopic Examination, Fig. I. 270 
Fig- II 270 
Fig. Ill 270 
Fig. IV 271 
Deductions therefrom ............ 271 
Probable errors in Hurst's classification 271 
Rarity of pure blue or grey, or pure blue and grey parentages . . . 272 
Observations on blue eyes with deductions 272 
Remarks on the pedigrees of Iris pigmentation ....... 273 
Conclusions 275 
Pedigrees of Iris pigmentation 276 et seq. 
In the Proceedings of the Royal Society (B), Vol. 80, 1908, p. 85, C. C. Hurst 
has published a paper " On the Inheritance of Eye-Colour in Man." He therein 
states that there is distinct discontinuity between : 
(1) " The eyes in which two kinds of pigments are present ; the one yellow- 
brown in colour, deposited on the outer or anterior surface of the iris ; the other, 
blue-black in colour, deposited on the inner or posterior surface of the iris." 
Such eyes he calls duplex. 
(2) " The eyes in which the posterior pigment alone is present in the iris, the 
anterior pigment being absent." Such eyes he calls simplex. 
At page 93 he states that " (1) simplex parents mated together give all simplex 
offspring ; (2) duplex parents mated together give either (a) all duplex offspring, 
34—2 
