That which was primarily a holy instinct became, in its perversion, a source of evil and a cause of dread; hence the serpent became a representative of evil itself, and the conflict with it was the conflict between good and evil, between light and darkness. This is shown in the religions of ancient Babylonia, Egypt, and India, and Phœnicia and Greece, and Mexico and Peru, and various other countries.[620] Vishnoo and his wife Lakshmi, from whom, according to Hindoo teachings, the world was produced, and by whom it continues or must cease, are represented as seated on a serpent, as the basis of their life and power.[621] Siva, also, giver and destroyer of life, is crowned with a serpent, and a serpent is his necklace, while the symbol of his worship is the _linga in yoni_.[622] A mode of Hindoo worship includes the placing of a stone _linga_ between two serpents, and under two trees, the one a male tree and the other a female tree.[623] And in various ways the serpent appears, in connection with different Hindoo deities, as the agent of life-giving or of life-destroying.[624] A suggestive representation of Booddha as the conqueror of desire shows him seated restfully on a coiled serpent, the hooded head of which is a screen or canopy above his head.[625] Apollo, son of Zeus, was the slayer of the man-destroying serpent at Delphi; yet the serpent, when conquered, became a means of life and inspiration to others.[626] Æsculapius, the god of healing, a son of Apollo, was represented by the serpent because he gave new life to those who were dying. Serpents were everywhere connected with his worship as a means of healing.[627] The female oracle who represented Apollo at Delphi sat on a tripod formed of entwined serpents.[628] Serpents on the head of Medusa were a means of death to the beholder; and these serpents were given to Medusa instead of hair because of her faithlessness and sacrilege in the matter of the Threshold Covenant.[629] Thus the good and the evil in that which the serpent symbolized were shown in the religions of the nations of antiquity, and serpent worship became one of the grossest perversions of the idea of the primitive Threshold Covenant. As in the matter of phallic worship and tree worship, so in this of the worship of the serpent, it would seem unnecessary to multiply illustrations of its prominence in various lands, when so many special treatises on the subject are already available.[630] It is only necessary to emphasize anew the fact that the evident thought of the symbol is an outgrowth or a perversion of the idea of the primitive Threshold Covenant.