Wilson — The Inheritance of Coat Colour in Horses. 347 



It will be seeu from the above table that a few greys are produced when 

 roans are mated with ordinary colours. If we could be assured that these are 

 really greys, and that the parents are correctly described, the problem of the 

 relative positions of roan and grey would be solved ; but such assurance is 

 impossible with colours so liable to confusion as roan and grey. If a similar 

 table of grey matings with ordinary colours were made out, it would show 

 the contrary phenomenon of roans being produced by the greys, and so 

 would suggest that grey is dominant to roan. For the present, therefore, 

 the relative positions of grey and roan must remain undecided. 



One other colour, dun, remains; but although some dun entries were 

 seen in each of the three stud-books drawn upon, they were far too few for 

 our purpose, and were not noted. 



But from statements published by Weldon and Cossar Ewart, and from 

 information given by Mr. P. Macginnis as to foals produced by dun sires 

 in county Londonderry, the following small table can be formed : — 



Ch. Bl. By. Bv. Gr. Rn. Dun. 

 1 dun X 1 cliestnut gives - - 1 - - - 1 



1 dun X 1 black ,, - l - _ _ _ 2 



1 duB X 2 bays „ i i i _ _ i i 



1 dun X 1 dun „ l _ 1 _ _ _ 2' 



2 dun X 6 grey mares ,, - - - 2 2 - 4 



It is apparent from the first two and the last of these matings that dun 

 contains, i.e., is dominant to, chestnut, black, and bay. The matings of dun 

 and grey give no indication. But from information received on Clare Island 

 last July it seems certain that dun is dominant to brown also. Some time 

 ago a dun Norse sire which was brought to the island left a number of dun 

 foals from a population consisting chiefly of bay and brown mares ; and 

 these dun foals when themselves put to a brown sire threw some dun foals 

 again. This places dun dominant to brown, bay, black, and chestnut ; but 

 leaves its position with regard to grey and roan unknown.^ 



It may be well to reiterate the statement made at the beginning of 

 this paper, that stud-book data are far from being absolutely accurate, and 

 that the validity of our conclusions must depend upon tlie success with which 

 the inaccuracies of the stud-book have been smoothed out. It is hoped 



' One of these is called yellow. 



- Since this paper was read a case has been found, in Professor Cossar Ewart' s paper on " The 

 Multiple Origin of Horses and Ponies," of two greys producing a dun. This would show that dun 

 is recessive to grey. 



SCIENT. PBGC., B.D.S., VOL. XII., NO. XXVIII. 3k 



