Little by little they are arranged in groups. The Celts, for instance, coming to river after river in their onward march, employed the same name again and again, "Deuona," divine (still surviving in this country in different forms, Devon, Dee, etc.), as though all rivers belonged to one power. They were the givers of life and health and plenty, to whom costly sacrifices must be made. So they might bear the title "Mother," and were akin to the powers of fertility living in the soil, the "Mothers" (_Matres_ or _Matronæ_), cognate with the "Mothers" who fulfil similar functions in modern India. The adjacent Teutonic peoples filled forest and field with wood-sprites and elves, dwellers in the air and the sunlight. The springs, the streams, and the lakes, were the home of the water-sprites or nixes; in the fall of the mighty torrent, among the rocks on the mountain heights, in the fury of the storm or the severity of the frost, was the strength of the giants. Yet further east and north the Finnic races looked out on a land of forest and waters, of mists and winds. The spirits were ranged beneath rulers who were figured in human form. The huntsman prayed with vow and sacrifice to the aged Tapio, god of the woods and the wild animals. Kekri watched over the increase of the herd, while Hillervo protected them on the summer pastures. The grains and herbs--of less importance to tribes {105} only imperfectly agricultural--were ascribed to the care of Pellervoinen, who falls into the background and receives but little veneration. Water, once worshipped as a living element (_vesi_), is gradually supplanted by a water-god (Ahto) who rules over the spirits of lakes and rivers, wells and springs. "Mother-earth" still designates in the oldest poetry the living energy of the ground, though she afterwards becomes the "lady of the earth" and consort of the lord of the sky. The sky, Jumala, was first of all conceived as itself living; "Jumala's weather" was like "Zeus's shower" to an ancient Greek. And then, under the name Ukko, the sky becomes a personal ruler, with clouds and rain, thunder and hail, beneath his sway; who can be addressed as-- Ukko, thou of gods the highest, Ukko, thou our Heavenly Father.