The custom of transferring disease or sickness from men to trees is well known. Sometimes the hair, nails, clothing, etc., of a sickly person are fixed to a tree ; or they are forcibly inserted in a hole in the trunk, or the tree is split and the patient passes through the aperture. Where the tree has been thus injured, its recovery and that of the patient are often associated. In India when a man is supposed to be tormented by a demon, ceremonies are performed to provide it with a tree where it will dwell peace fully without molesting the patient so long as the tree is left unharmed. Such ideas do not enter, of course, when the rite merely removes the illness, but endangers the health of those who approach the tree. Again, sometimes it is believed that man's personality is mystically united with some healthy and sturdy tree, and in this case we may often presume that such trees already possessed some appropriate reputation. Again hair, nail-clippings, etc., are hung upon a tree for safety's sake lest they fall into the hands of an enemy.
Spirits in Trees.—Among the Arabs the sacred trees are haunted by angels or by jinn; sacrifices are made, and the sick who sleep beneath them receive prescriptions. Here, as frequently elsewhere, it is dangerous to pull a bough. This dread of damaging special trees is familiar: Cato instructed the woodman to sacri fice to the male or female deity before thinning a grove (De re rustica, 139), while in the Homeric poem to Aphrodite the tree nymph is wounded when the tree is injured, and dies when the trunk falls. Early Buddhism decided that trees had neither mind nor feeling and might lawfully be cut ; but it recognized that cer tain spirits might reside in them, and this the modern natives of India firmly believe. Propitiation is made before the sacri legious axe is laid to the holy trees ; loss of life or of wealth and the failure of rain are feared should they be wantonly cut ; and there are even trees which it is dangerous to climb. The Talein of Burma prays to the tree before he cuts it down, and the African woodman will place a fresh sprig upon the stump as a new home for the spirit. In the Gold Coast the silk-cotton and odum (poison) trees are especially sacred as the abode of the two deities, who are honoured by sacrifices—even of human victims; these can be felled only after certain purificatory ceremonies. In general, sacred trees must not be injured unless they (i.e., their spirits) have been appeased, or means taken to provide the occupant with another abode. That the difference between the sacred object and the sacred occupant was not always clearly drawn is quite intelligible from those beliefs of much less rudi mentary religions which confuse the unessential with the essential.
Forms of Cult.—Often the tree is famous for oracles. One of the best known is the oak of Dodona tended by priests who slept on the ground. The tall oaks of the old Prussians were inhabited by gods who gave responses, and the old Hebrews had their "terebinth of the teacher" (Gen. xii. 6), and "terebinth of the diviners" (Judg. ix. 37). Sacred trees are also the object of pilgrimage, one of the most noteworthy being the branch of the Bo tree at Ceylon brought thither before the Christian era. Again, tree-spirits will hold sway over the surrounding forest or dis trict, and the animals in the locality are sacred and must not be harmed. Thus, the pigeons at the grove of Dodona, and the beasts around the north European tree-sanctuaries, were left un touched ; even as the modern Dyak allows no interference with the snake by the side of the bush which enshrines a dead kinsman. Sacred fires burned before the Lithuanian Perkuno and the Roman Jupiter; both deities were closely associated with the oak, and, indeed, according to Frazer, the oak seems to have been very com monly used for the perpetual holy fires of the Aryans.
The powers of the tree-deities, though often specially con nected with the elements, are not necessarily so restricted, and the sacred trees can form the centre of religious, and sometimes, also, of national life. Such deities are not abstract beings, but are potent and immediate, and the cultus is primarily as utilitarian as the duties of life itself. They may have their proper mm istrants : the chief sanctuary of the old Prussians was a holy oak around which lived priests and a high priest known as "God's mouth '; in Africa there are sacred groves into which the priest alone may enter, and among the Kissil-Bashi (or Kizilbashes) of the Upper Tigris and Euphrates, the holy tree of the village stands in an enclosure to which only the father-priest has access. The trees may be the scene of religious festivals and of periodical fairs and markets. Among the Lousiade group in British New Guinea the religious feasts are held under the sacred tree and a portion is laid aside for the spirit-occupants. That the invisible spirit naturally enjoyed only the spiritual part of the offerings is a belief which has been shared by others than the African negro (Tylor ii. 216). Human sacrifice is known on the Slave Coast and in the Punjab; it was practised among the Druids, and at Odin's grave at Uppsala. It is also said that the pollution of old Prussian sacred groves and springs by the intrusion of Christians was atoned for by human victims.