THE COLOUR OF HOUSES

Evening Post, Volume 105, Issue 4, 6 January 1928, Page 5

THE COLOUR OF HOUSES

• GREYS AND THEIR CONTINUITY Arising out of a discussion of the colour of horses and whether the grey hairs are really hereditary, "Snowden" of the "Australasian goes into the matter thoroughly. He writes:— Black, bay, and brown coats behave iv heredity as alternative characters to chestnut, which is recessive to them. Grey is of different character altogether. It is neither dominant nor recessive, but is really an additional characteristic. Grey is a mosaic of dark and white hairs, and if these hairs be examined under a microscope they are found to be devoid of •pigment, but the skin of a grey is intensely pigmented. These two facts give the clue to greyness, namely, a peculiarity in the minute thread-like channels which connect the pigment producing cells with the hair follicles. A full complement of pigment necessary to colour the whole of the coat is present in the skin of greys, but something prevents or inhibits the flow of pigment from the "factories into certain of the hairs. Very probably there is a structural modification in the tiny canals rendering them too small to allow of the passage of pigment granules. In short, grey or roan is a whole-colour with an added character which represses pigmentation of some or all of the hairs. Were it possible to remove this character which prevents the flow of pigment into the hair the grey or roan would become whole coloured at once, that is black, bay, brown, or chestnut, according to the nature of the colour factors inherited in each particular case. Eoi Herode and The Tetrarch, for instance, would have been chestnut; the Victorian performer Archelaus would have been black or brown, Potentate a chestnut, and so on. GREY AN ADDED COLOUR. This structural peculiarity, which is the cause of greyness, is transmitted in heredity independently of the determining factors for the various coat colours. It is an added character which all whole colours lack) and it; baa--for its alternative its absence, Which iii;'effect" is normal pigmentation of the hair. Nearly all greys are hybrid greys, that is, they are born wholecolour, but in time the inhibition inherited from one parent begins to make itself evident, and the animal's coat colour becomes grey. On Stud Book evidence there are many apparent exceptions to the fact that a grey jiorse must have at least one grey parent.: Many foals which are returned as whole colour to the Stud Book in time follow the colour of their grey parent, but no correction is made of the' first return. But when the animals race the correct colour is invariably given in the race records. There are a number of cases in the Australian Stud Book where mares recorded as whole colour have bred greys to whole-coloured sires. But those mares have been wrongly described by the coat returned when they were foals, and not when the inhibition had been made manifest some time after. For instance, that game little galloway Little Marg (grey), by Prudent King (brown), is, according to the Stud Book, out of a bay mare, TheOdasia. Theodasia was bay when she was foaled, but before she was a four-year-old she had become grey.' Chris Moore raced her, as he did Theodasia's year older sister Crete. But Crete did not inherit the inhibition, and she remained a bay. The greyness was therefore lost to the Crete channel, and that is why it could not be handed down to Crete's descendants, Naloori and The Cretan. Crete (by the bay Amherst) was bred by the late Dr. Lang, and her dam, the grey mare Ariadne, was in foal again to Amherst (the foal being Theodasia), when she was passed on to Mr. James Wilson. Ariadne got her colour from her dam Governess, who was.by the famous grey horse Lecturer, son of the grey mare Sappho, a daughter of the older grey Sappho, a daughter of a grey mare, by the grey horse Zohrab, whose dam was the imported grey mare1 Gulnare, by the grey horse Young Gohanna, whose colour came down through, several generations in the female line from Crab's grey daughter Hag. TWO LINES ONLY EXTANT. In the early history of the thoroughbred there,were many individual sources of grey, but the colour of present-day greys has been inherited through an unbroken line from one of two grey stallions, Alcock's Arabian (also known as Mr. Pelham's grey Arab) and the Brown low Turk. Both were imported to England in the early years of the eighteenth century. Tho •grey lino tracing solely to the Brownlow Turk has almost died out, but the Roi Herode line brings in both the Brownlow Turk and Alcock's Arabian, and, curiously, there is a double cross of these grey lines. Crab, the son of Alcock's Arabian, was mated with a Childers mare of Brownlow Turk blood, and iv later generations a female descendant from Crab was mated with a horse who traced back to Blossom the progeny of the Crab —Childers mare alliance. A detailed table shows that the grey came down from Alcock's Arabian to Snowden through only eight individuals, yet if the pedigree of Snowden were run out to nine generations it would show in the last line of the tabulation 512 names (of which Alcock's Arabian passing on the grey colour would appear only once) and in the whole nine generations 1022 names Still more amazing does the persistence of the grey become when stock is taken of Sarchedon. if the pedigree of the Northwood Park horse were tabulated back for 20-generations, Alcock's Arabian would be one name in a column of more than 1,000,000 names, and if it were extended another two generations to take in the name of the Brownlow Turk that horse's name would appear in a column containing more than 4,000,000 names. Yet through all that maze there are only 21 grey individuals holding the line between the Brownlow Turk and Sarchedon, and only 19 between Sarchedon and Alcock's Arabian!