116 On Heterochromia Iridis in Man and Animals 



in both. The self mating of a pair of the "harlequin" hybrids of the 

 "A" cross produced in six years: 



Black and White 

 Blacks Blues Harlequin Whites 



11 4 17 22 (Total = 54) 



The self mating of a pair of the "black" hybrids of the "B" cross 

 produced in the same time : 



Black and White 



Whites 



16 (Total = 81) 



see Chart, pp. 118, 119. 



It is of interest to compare this result in pigeons with the two 

 extracted types of the " Irish " variety in hooded rats obtained by 

 Doncaster and Mudge by crossing the wild grey with the albino rat 

 (Bateson(9), p. 84). 



On re-mating the original black cock of the "A" mating to another 

 white fantail hen of a different strain ("C" mating) all the offspring F^ 

 were blacks with white rump feathers and white wing primaries like 

 the Fi black offspring of the " B" cross. 



This result of the second mating shows that the difference in parental 

 gametic constitution which led to the difference in colour pattern in the 

 .Fi hybrids of the "A" and " B" crosses was introduced by thewhite recessive 

 female parent of the "A" cross, and it is this difference of gametic 

 constitution in this parent that led also to the unequal distribution of 

 extracted types and the excess of recessive whites in the F„ generation 

 of the "A" cross over that in the JP, generation of the " B " cross\ The 

 association between eye colour and feather colour was preserved in 

 these parallel matings, the harlequin Fi offspring of the "A" cross 

 retaining the " bull " eye and the black Fi offspring of the "B" mating 

 the orange eye. The bull eye of these F^ and extracted F„ harlequin 

 birds, however, has a pinker appearance than the bull eye of the normal 

 white fantail-. 



Heterochromia in cats. 



In his experiments on heterochromia in Angora cats in 1907, 

 Przibram (7) found that the mating of an asymmetrically coloured 

 animal having one blue and one yellow eye with a symmetrically 



1 The distribution of recessives, intermediates and dominants as revealed in the charts 

 (pp. 118, 119) suggests a grouping of these three classes of offspring, especially in the case 

 of the white recessive bii-ds. 



2 In both matings the recessive whites showed the " bull " and the dominant blacks 

 the orange eye. 



