The Irish _bile_ was a sacred tree, of great age, growing over a holy well or fort. Five of them are described in the _Dindsenchas_, and one was an oak, which not only yielded acorns, but nuts and apples.[673] The mythic trees of Elysium had the same varied fruitage, and the reason in both cases is perhaps the fact that when the cultivated apple took the place of acorns and nuts as a food staple, words signifying "nut" or "acorn" were transferred to the apple. A myth of trees on which all these fruits grew might then easily arise. Another Irish _bile_ was a yew described in a poem as "a firm strong god," while such phrases in this poem as "word-pure man," "judgment of origin," "spell of knowledge," may have some reference to the custom of writing divinations in ogham on rods of yew. The other _bile_ were ash-trees, and from one of them the _Fir Bile_, "men of the tree," were named--perhaps a totem-clan.[674] The lives of kings and chiefs appear to have been connected with these trees, probably as representatives of the spirit of vegetation embodied in the tree, and under their shadow they were inaugurated. But as a substitute for the king was slain, so doubtless these pre-eminent sacred trees were too sacred, too much charged with supernatural force, to be cut down and burned, and the yearly ritual would be performed with another tree. But in time of feud one tribe gloried in destroying the _bile_ of another; and even in the tenth century, when the _bile maighe Adair_ was destroyed by Maelocohlen the act was regarded with horror. "But, O reader, this deed did not pass unpunished."[675] Of another _bile_, that of Borrisokane, it was said that any house in which a fragment of it was burned would itself be destroyed by fire.[676] Tribal and personal names point to belief in descent from tree gods or spirits and perhaps to totemism. The Eburones were the yew-tree tribe (_eburos_); the Bituriges perhaps had the mistletoe for their symbol, and their surname Vivisci implies that they were called "Mistletoe men."[677] If _bile_ (tree) is connected with the name Bile, that of the ancestor of the Milesians, this may point to some myth of descent from a sacred tree, as in the case of the _Fir Bile_, or "men of the tree."[678] Other names like Guidgen (_Viduo-genos_, "son of the tree"), Dergen (_Dervo-genos_, "son of the oak"), Guerngen (_Verno-genos_, "son of the alder"), imply filiation to a tree. Though these names became conventional, they express what had once been a living belief. Names borrowed directly from trees are also found---Eburos or Ebur, "yew," Derua or Deruacus, "oak," etc.