2 MR. ADAIR DIGHTON ON 



From the point of view of accuracy in the present statistics it 

 is unfortunate that colour registration should have to be made 

 at so early an age, for there is no doubt that in many cases 

 colour changes with age, and there may be, in fact are, cases in 

 which the colour would have been registered differently had the 

 date of registration been postponed. There is one other point 

 to which I would draw your attention. Under the heading of 

 " Registration Regulations" there is the following instruction: — 



"It is not desirable to register a colour which is not seen 

 by the judge when following the dogs. Thus it often 

 happens that a black dog has an insignificant patch of white 

 on his chest, it may be a few white hairs on the tip of his 

 tail or a white toe. The entry of such a dog as black and 

 white simply leads to confusion, and should be avoided." 



From the practical standpoint this is an excellent rule, but it is 

 not conducive to that accuracy in description which is of such 

 vital importance when dealing with colour from a scientific or 

 statistical point of view. 



Bearing these points in mind, I began with the Grey- 

 hound Stud Book for the year 1907, and have worked through the 

 fifteen succeeding volumes up to, and including, that pub- 

 lished in 1921. In this way the records of 16,260 litters have 

 been examined and the colotirs of 25,767 whelps have been 

 tabulated. The pigmentary factors of greyhounds resemble those 

 of other animals in that they consist of black, chocolate (known 

 as red), and yellow. In addition, the greyhound has a composite 

 colour known as brindle, which is due to a pattern factor 

 combining with one, or more, of the other colours. The results, 

 generally, may be taken to represent the actual colours of the 

 various individuals, but personal observation shows that there 

 are certain discrepancies. Thus there are blacks, so registered, 

 that show brindle markings, and the returns do not differentiate, 

 in the majoi-ity of cases, between red and fawn, the usual descrip- 

 tion being " red or fawn," which explains why it has been 

 necessary for me to group these two colours together under one 

 heading. Pure albinism of the skin and hair is very rare, but 

 partial albinism is common io the pied patterns. Other colours, 

 or combinations of colours, such as blue-brindle, blue-fawn, black- 

 brindle, etc., are often met with, but these are too ambiguous to 

 be taken into account and are not included in my figures. 



Take first the matings of black to black. On the assumption 

 that black and blue are dominant over all other coat colours, 

 the blacks can be of two kinds : pure dominant blacks, containing 

 nothing but black factoi's, and impure dominant blacks, con- 

 taining one black factor and one alternative factor, which may 

 be either brindle, or red, or fawn. Now, though pure dominants 

 do occur in all colours, they are rare. Greyhounds are bred 

 for speed and work. Colour is a minor consideration, and of the 

 thousands of dogs born, only a very small percentage of them 



