The early Dravidian religion constituted a non-Vedic form of Hinduism in that they were either historically or are at present Āgamic. The Agamas are non-Vedic in origin, and have been dated either as post-Vedic texts, or as pre-Vedic compositions. The Agamas are a collection of Tamil and Sanskrit scriptures chiefly constituting the methods of temple construction and creation of murti, worship means of deities, philosophical doctrines, meditative practices, attainment of sixfold desires and four kinds of yoga. The worship of tutelary deity, sacred flora and fauna in Hinduism is also recognized as a survival of the pre-Vedic Dravidian religion. Dravidian linguistic influence on early Vedic religion is evident, many of these features are already present in the oldest known Indo-Aryan language, the language of the Rigveda (c. 1500 BCE), which also includes over a dozen words borrowed from Dravidian. The linguistic evidence for Dravidian impact grows increasingly strong as one moves from the Samhitas down through the later Vedic works and into the classical post-Vedic literature. This represents an early religious and cultural fusion or synthesis between ancient Dravidians and Indo-Aryans that went on to influence Indian civilization.