Lastly, in the great alluvial plain which separates the Himalayas from the tableland of the south, and along the western coast, are the peoples who use one or other of the great Aryan vernaculars, languages of much the same type as the modern languages of Europe, sharing much of their vocabulary, and ultimately derived from similar if still obscure origins. It is of all these languages, and of some of their innumerable dialects (not all of them even now known by name), that some account must be given in this chapter. * * * * * The history of the languages of India has reflected the long struggle for pre-eminence between the indigenous Dravidian culture of the south and the Aryan civilisation of the north. The Mundā languages are those of an isolated group of highlanders, who, till quite recent times, hardly came into contact with or were influenced by the speech or thought of other races. The Mon-Khmer-speaking people of the Khasi Hills were similarly wholly isolated, and were long supposed to be absolutely aboriginal and separate from other races of men, till quite recent investigations discovered their linguistic affinities with the Mons of Southern Burma and races in French Indo-China. The Tibeto-Burman languages of the north-eastern frontier are the simple and primitive speech of semi-savage men. For such languages, contact with the Aryan languages means rapid decay and dissolution. Hindu civilisation and Hindu religion find easy converts in the rude and simple Mongoloid people of the north-east, and acceptance of Hindu manners and customs almost always results in a rapid change of language. So again, the Iranian languages represent the final stage in the advance of Islam and its languages as a conquering religion. The Iranian tongues of the north-western frontier are only Indian in the fact that they happen to fall within the administrative border of British India. If we omit all consideration of these races and languages for the present, we shall be free to consider the long struggle between the Aryan and the Dravidian. The Aryan religion, the religion of the Hindus, has spread all over India, and as the Dravidian temples of the south are among the glories of Hindu religious architecture, so the Hinduism of the south is now, in many ways, the most typical and interesting form of the religion. The spread of the Aryan blood has been far less wide in extent, as the previous chapter sufficiently shows. The Aryan languages have spread all over the north of India, up to an irregular line running obliquely across the peninsula from near Vizagapatam on the east coast to near Goa on the west coast. Into the Aryan area projects the rocky plateau of Chota Nagpore, where the Mundā dialects still survive, and there are a few other outlying areas where Dravidian tribes still use the original language of India. With these exceptions, Northern India, from Bombay to Calcutta now speaks Aryan languages.