beneath the sea, a lake, or a river, or it is approachable only through some cave or opening in the earth.  In the hunting-grounds of the Celtic world the primitive hunter knew every cranny of the greater part of his environment with the accuracy born of long familiarity, but there were some peaks which he could not scale, some caves which he could not penetrate, some jungles into which he could not enter, and in these he knew not what monsters might lurk or unknown beings might live.  In Celtic folk-lore the belief in fabulous monsters has not yet ceased.  Man was surrounded by dangers visible and invisible, and the time came when some prehistoric man of genius propounded the view that all the objects around him were no less living than himself.  This animistic view of the world, once adopted, made great headway from the various centres where it originated, and man derived from it a new sense of kinship with his world, but also new terrors from it.  Knowing from the experience of dreams that he himself seemed able to wander away from himself, he thought in course of time that other living things were somehow double, and the world around him came to be occupied, not merely with things that were alive, but with other selves of these things, that could remain in them or leave them at will.  Here, again, this new prehistoric philosophy gave an added interest to life, but it was none the less a source of fresh terrors.  The world swarmed with invisible spirits, some friendly, some hostile, and, in view of these beings, life had to be regulated by strict rules of actions and prohibitions.  Even in the neolithic stage the inhabitants of Celtic countries had attained to the religious ideas in question, as is seen not only by their folk-lore and by the names of groups of goddesses such as the Matres (or mothers), but by the fact that in historic times they had advanced well beyond this stage to that of named and individualised gods.  As in all countries where the gods were individualised, the men of Celtic lands, whether aborigines or invaders, had toiled along the steep ascent from the primitive vague sense of being haunted to a belief in gods who, like Esus, Teutates, Grannos, Bormanus, Litavis, had names of a definite character.

Among the prohibitions which had established themselves among the races of Celtic lands, as elsewhere, was that directed against the shedding of the blood of one’s own kin.  There are indications, too, that some at any rate of the tribes inhabiting these countries reckoned kinship through the mother, as in fact continued to be the case among the Picts of Scotland into historic times.  It does not follow, as we know from other countries, that the pre-Aryan tribes of Gaul and Britain, or indeed the Aryan tribes themselves in their earliest stage, regarded their original ancestors as human.  Certain names of deities such as Tarvos (the bull), Moccos (the pig), Epona (the goddess of horses), Damona (the goddess