But though the outline of Śiva is found in Vedic writings, later centuries added new features to his cult. Chief among these is the worship of a column known as the Linga, the emblem under which he is now most commonly adored. It is a phallic symbol though usually decent in appearance. The Vedas do not countenance this worship and it is not clear that it was even known to them.[345] It is first enjoined in the Mahâbhârata and there only in two passages[346] which appear to be late additions. The inference seems to be that it was accepted as part of Hinduism just about the time that our edition of the Mahâbhârata was compiled.[347] The old theory that it was borrowed from aboriginal and especially from Dravidian tribes[348] is now discredited. In the first place the instances cited of phallic worship among aboriginal tribes are not particularly numerous or striking. Secondly, linga worship, though prevalent in the south, is not confined to it, but flourishes in all parts of India, even in Assam and Nepal. Thirdly, it is not connected with low castes, with orgies, with obscene or bloodthirsty rites or with anything which can be called un-Aryan. It forms part of the private devotions of the strictest Brahmans, and despite the significance of the emblem, the worship offered to it is perfectly decorous.[349] The evidence thus suggests that this cultus grew up among Brahmanical Hindus in the early centuries of our era. The idea that there was something divine in virility and generation already existed. The choice of the symbol--the stone pillar--may have been influenced by two circumstances. Firstly, the Buddhist veneration of stûpas, especially miniature stûpas, must have made familiar the idea that a cone or column is a religious emblem,[350] and secondly the linga may be compared to the carved pillars or stone standards erected in honour of Vishṇu. Some lingas are carved and bear one or four faces, thus entirely losing any phallic appearance. The wide extension of this cult, though its origin seems late, is remarkable. Something similar may be seen in the worship of Gaṇeśa: the first records of it are even later, but it is now universal in India.