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Scientific Proceedings, Royal Duhlin Society. 



dominant. But there is a very peculiar difference. The grey colour domi- 

 nates the other colours below it entirely ; roan does not. The grey foal of a 

 bay dam and a grey sire is grey ; but the roan foal of, say, a bay dam and a 

 roan sire will have the body a mixture of white or grey hairs in a back-ground 

 of bay or any of the other usual colours, while, so far as can be seen as yet, 

 the leg-markings will be those usually associated with the back-ground. A 

 bay or brown roan will have black " points," the legs of a chestnut-roan will 

 be chestnut, and so on. 



And still further : the back-ground colours seem to behave to each other, 

 so far as dominance is concerned, as they do when no grey hairs are present 

 to make tliem roans. That is to say : two chestnut-roans seem to produce 

 only chestnuts and chestnut-roans , while two brown-roans seem to produce 

 brown-roans, bay-roans, black-roans (perhaps also blue-roans), chestnut-roans, 

 and another colour, strawberry-roan, which seems to depend rather upon the 

 quantity of grey hairs present than upon the colour of the back-ground. It 

 would almost seem as if the grey hairs in roan parents allowed the back- 

 ground colours to work as they do ordinarily, but that they introduced them- 

 selves to the coat of about every second foal. These ideas have been suggested 

 while tabulating the results of roan matings, but the data are still too few to 

 say they are proved. 



The source of roan, that is of the white hairs that make other coats roan, 

 has not been found. Nor are the relative positions of roan and grey clear. 

 Roan behaves like grey with the other colours below grey ; but the crossings 

 between grey and roan are too few for any inference. 



Meantime let us set down a table showing the results of crossings with 

 roans (vol. xi. to xv.), in which the roans are subdivided into roans, 

 blue-roaus, and iron-greys (which are probably grey- roans) : — 



