Some idea of the extraordinary predominance of Jack in the stud may be gathered from the entries in the first nine volumes of the ‘Shetland Pony Stud-Book,’ in whose tenth volume the dispersal sale of the stud at Seaham Harbour is recorded. We find that in the period covered by these entries, nineteen stud horses were used to a greater or less extent. Of these, in addition to Jack himself, there were his three sons, Laird of Noss (20), Lord of the Isles (26), and Odin (32); and his eight grandsons, Thor (83), Sigurd (103), Emeer (131), Runolf (62), Najal (75), Lava (121), and Otkell; while Oman (33), his great-grandson on the dam’s side, was also considerably used. We find also that these ponies related to Jack were much more extensively bred from than the unrelated sires, so that of the four hundred and ninety foals entered as produce, two hundred and forty-eight are by Jack and his three sons, and a hundred and sixty by his eight grandsons; while thirty-six are by Oman, and only forty-six by sires wholly unrelated to Jack.
JACK (16).
An analysis of the list of dams bred from in the stud accentuates the meaning of these figures; since out of a total of a hundred and twenty-five entered in the Stud-Book, seventy-six are by Jack and his three sons, while ten are by his grandsons.
The result of this selection of breeding stock appears in the extent to which the progeny are inbred to Jack. Of the hundred and twenty-five mares, fifty are sired by Jack, his sons, and grandsons, out of dams similarly sired; while forty are sired by Jack and his three sons, out of mares sired by them. Of the four hundred and ninety foals entered, two hundred and eighty-two are sired by Jack and his sons and grandsons, out of mares by the same list of sires.
Of the fifty-one mares not bred from Jack and his direct descendants, twelve were daughters of Prince of Thule (36), and thirty-six by his son Oman.
Prince of Thule is thus, next to Jack and his sons, the most important sire element in the stud. His influence, however, is considerably reduced by the almost exclusive extent to which he was mated with mares sired by Jack and his sons. Of the twelve mares sired by him, seven are from daughters of Jack, one from a daughter of Odin, and one from a daughter of Laird of Noss; while twenty-four of the dams of his thirty-four foals are daughters of Jack and his three sons.
The influence of his son Oman is similarly discounted, five of his six daughters bred from being daughters of Jack’s sons, while twenty-eight of all his thirty-six foals have dams similarly bred.