Wherever an ancestor of the Alcheringa[794] times is believed to have entered into the ground, there is either a stone or a tree representing his body. The tree or rock which has this mystic relation with the departed hero is called _nanja_ according to Spencer and Gillen,[795] or _ngarra_ according to Strehlow.[796] Sometimes it is a water-hole which is believed to have been formed in this way. Now, on each of these trees or rocks and in each of these water-holes, there live embryo children, called _ratapa_,[797] which belong to exactly the same totem as the corresponding ancestor. For example, on a gum-tree representing an ancestor of the kangaroo totem there are ratapa, all of which have the kangaroo as their totem. If a woman happens to pass it, and she is of the matrimonial class to which the mothers of these ratapa should belong,[798] one of them may enter her through the hip. The woman learns of this act by the characteristic pains which are the first symptoms of pregnancy. The child thus conceived will of course belong to the same totem as the ancestor upon whose mystical body he resided before becoming incarnate.[799] In other cases, the process employed is slightly different: the ancestor himself acts in person. At a given moment he leaves his subterranean retreat and throws on to the passing woman a little churinga of a special form, called _namatuna_.[800] The churinga enters the body of the woman and takes a human form there, while the ancestor disappears again into the earth.[801] These two ways of conception are believed to be equally frequent. The features of the child will reveal the manner in which he was conceived; according to whether his face is broad or long, they say that he is the incarnation of a ratapa or a namatuna. Beside these two means of fecundation, Strehlow places a third, which, however, is much more rare. After his namatuna has penetrated into the body of the woman, the ancestor himself enters her and voluntarily submits to a new birth. So in this case, the conception is due to a real reincarnation of the ancestor. But this is very exceptional, and when a man who has been conceived thus dies, the ancestral soul which animated him goes away, just like ordinary souls, to the isles of the dead where, after the usual delays, it is definitely annihilated. So it cannot undergo any further reincarnations.[802] Such is the version of Strehlow.[803] In the opinion of this author it is radically opposed to that of Spencer and Gillen. But in reality it differs only in the letter of the formulæ and symbols, while in both cases we find the same mythical theme in slightly different forms.