A second and larger chamber, composed of cave slabs of limestone, was discovered in the same cairn in 1871 by the Rev. D. R. Thomas, and completely excavated by him along with myself and the Rev. H. H. Winwood. It was of a rudely triangular form, 10 feet long by 6 wide, traversed by a partition of slabs, and provided with a narrow passage 10 feet long by 2 feet 6 in width, opening to the north, and fenced off completely from the chamber by a slab, as in the preceding case. Both the chamber and the passage were full of human remains of all ages, buried in a contracted posture; the number of interments being far too great to have allowed the bodies to have been deposited at one time. From the former I identified the broken jaw of a roebuck and remains of goat, a broken flint, and round pebbles of quartz, while in the latter there were the teeth and bones of the dog and the pig. Some of the tibiæ from both the chambers were platycnemic, but that character was only to be recognized in the older bones. The skulls, from the second of the two chambers, agree so exactly with those from the caves, that it is not necessary to add to the table of measurements which Professor Busk has drawn up (p. 171). _Correlation of Chambered Tomb with Interments in the Caves of Perthi-Chwareu and Cefn._ Nor are we without evidence that the builders of this cairn belonged to the same race as those who buried their dead in the caves of Perthi-Chwareu and of Cefn. The crania and the limb-bones are identical, and in both the tombs and caves the dead were buried in a contracted posture. Why then, it may be asked, were the remains of animals so rare in the one and so abundant in the other? In my opinion this difference may be explained by the hypothesis, invented by Professor Nilsson, of the origin of chambered tombs.[101] The idea of the “gallery graves,” according to that high authority, was derived from the subterranean house in which the deceased lived, and in which he was buried after his death, after the fashion of the Eskimos at the present day. The plan of the houses, like that of the ancient Lycian dwellings described by Sir Charles Fellowes, was preserved in the tombs, and probably for many ages after houses were no longer made in that fashion; since the principle of conservatism and the force of custom are more deeply rooted in religious and solemn ceremonial than in the changes of every-day life. The rarity of the remains of the animals may be explained by the fact of these tombs never having been used as dwellings, while their abundance in the caves may be accounted for by the latter having been inhabited by man, and thus the idea of the dead resting in his own house would be the cause of burial both in caves and chambered tombs. It is not at all strange that the same race should have used both for sepulture, when we consider that a “gallery grave” is an artificial cave, and that natural caves are few in number.