Ashoke Mukherjee (2001), is critical of the attempts to identify the Rigvedic Sarasvati. Mukherjee notes that many historians and archaeologists, both Indian and foreign, concluded that the word "Sarasvati" (literally "being full of water") is not a noun, a specific "thing". However, Mukherjee believes that "Sarasvati" is initially used by the Rig Vedic people as an adjective to the Indus as a large river and later evolved into a "noun". Mukherjee concludes that the Vedic poets had not seen the palaeo-Sarasvati, and that what they described in the Vedic verses refers to something else. He also suggests that in the post-Vedic and Puranic tradition the "disappearance" of Sarasvati, which to refers to "under [the ground in the sands", was created as a complementary myth to explain the visible non-existence of the river.