Gulf, and settled in Arabia and along the banks of the Euphrates; while a third, which we call the Aryan or Indo-Germanic, covered India, Afghanistan, and Northern Persia, gradually extending along the northern shores of the Black Sea into Europe. Now, as already stated, the earliest known records of any race are the hymns of the _Rig-Veda_, composed among the Aryans of Northern Persia, probably from earlier traditions handed down to them from the older Iranian stock, or even from the still earlier Polynesians; and it is remarkable that in all ancient mythological records, as well as on monumental inscriptions, the same vein of solar myth as is found in the _Rig-Veda_ is clearly traceable beneath the accumulated mythological lore of future ages. The main idea in all mythologies seems to have been that of a saviour-deity conquering the evil genius of night, or winter, and bringing back the day, or summer, to replenish the earth. As already stated, Indra was to the Aryans of the early Vedic period the saviour-god who, with his companions, Vishnu and Rudra, leads forth Agni, the god of celestial and terrestrial fire, to the bosom of Varuna, where his influence operates upon Soma, the fertilizer of earth. A conqueror from early morn to mid-day, Indra’s power grows weaker as the evening approaches, until at last the twilight yields him up to Vritra, who slays him, after which he is tormented by Ahi, the dragon, for the remainder of the night. This drama was probably derived from the original Iranian stock, and as probably underwent considerable modification before being finally committed to writing as a cultus by the Aryans; and, therefore, we should expect to find some resemblance between the Aryan, Semitic, and Egyptian mythological systems. This is precisely what we do find on carefully comparing these three oldest of all known mythologies, though, as will be seen further on, each accumulates such a vast quantity of fresh mythological matter that the original conception is considerably obscured, and in each the original deities become in course of time so mixed up with one another that it is almost impossible to separate their individual characteristics.