The beauty of its berries, added to their brilliant red colour, would naturally excite feelings of admiration and awe, and hence it would in process of time become invested with a sacred significance.

It must be remembered, too, that all over the world there is a regard for things red, this colour having been once held sacred to Thor, and Grimm suggests that it was on this account the robin acquired its sacred character.

Similarly, the Highland women tie a piece of red worsted thread round their cows' tails previous to turning them out to grass for the first time in spring, for, in accordance with an old adage: "Rowan-ash, and red thread, Keep the devils from their speed." In the same way the mothers in Esthonia put some red thread in their babies' cradles as a preservative against danger, and in China something red is tied round children's wrists as a safeguard against evil spirits.
By the aid of comparative folk-lore it is interesting, as in this case, to trace the same notion in different countries, although it is by no means possible to account for such undesigned resemblance.

The common ash (_Fraxinus excelsior_), too, is a lightning plant, and, according to an old couplet: "Avoid an ash, It counts the flash." Another tree held sacred to Thor was the hazel (_Corylus avellana_), which, like the mountain-ash, was considered an actual embodiment of the lightning.

Indeed, "so deep was the faith of the people in the relation of this tree to the thunder god," says Mr.Conway,[5] "that the Catholics adopted and sanctioned it by a legend one may hear in Bavaria, that on their flight into Egypt the Holy Family took refuge under it from a storm." Its supposed immunity from all damage by lightning has long caused special reverence to be attached to it, and given rise to sundry superstitious usages.