Professor Rh[^y]s is disposed to accept the old idea that Stonehenge was the temple of Apollo in the island of the Hyperboreans, mentioned by Diodorus, where the sun-god was worshipped. But though that temple was circular, it had walls adorned with votive offerings. Nor does the temple unroofed yearly by the Namnite women imply a stone circle, for there is not the slightest particle of evidence that the circles were ever roofed in any way. Stone circles with mystic trees growing in them, one of them with a well by which entrance was gained to Tir fa Tonn, are mentioned in Irish tales. They were connected with magic rites, but are not spoken of as temples.
Lucan describes realistically the awful sacrifices of the Gauls on cruel altars not a whit milder than those of Diana, and he speaks of “altars piled with offerings” in the sacred grove at Marseilles. Cicero says that human victims were sacrificed on altars, and Tacitus describes the altars of Mona smeared with human blood. “Druids’ altars” are mentioned in the Irish “Expedition of Dathi,” and Cormac speaks of indelba, or altars adorned with emblems. Probably many of these altars were mere heaps of stone like the Norse horg, or a great block of stone. Some sacrifices, however, were too extensive to be offered on an altar, but in such cases the blood would be sprinkled upon it. Under Roman influence, Celtic altars took the form of those of the conquerors, with inscriptions containing names of native or Roman gods and bas-reliefs depicting some of these. The old idea that dolmens were Celtic altars is now abandoned. They were places of sepulture of the Neolithic or early Bronze Age, and were originally covered with a mound of earth. During the era of Celtic paganism they were therefore hidden from sight, and it is only in later times that the earth has been removed and the massive stones, arranged so as to form a species of chamber, have been laid bare.
The Gauls, according to Caesar, possessed plurima simulacra of the native Mercury, but he does not refer to images of other gods. We need not infer from this that the Celts had a prejudice against images, for among the Irish Celts images are often mentioned, and in Gaul under Roman rule many images existed.
The existence of images among the Celts as among other peoples, may owe something to the cult of trees and of stones set up over the dead. The stone, associated with the dead man’s spirit, became an image of himself, perhaps rudely fashioned in his likeness. A rough-hewn tree trunk became an image of the spirit or god of trees. On the other hand, some anthropomorphic images, like the palaeolithic or Mycenaean figurines, may have been fashioned without the intermediary of tree-trunk or stone pillar. Maximus of Tyre says