which are usually widely separated. The sciences of archaeology, philology, psychology and physiology must all be called upon to contribute to the elucidation of this problem."
When I received from Dr. Rivers a reprint of his classical monograph, I had begun to collect evidence regarding colour symbolism in ancient religious art and literature. I found it exceedingly helpful and stimulating, especially as it emphasised an aspect of the problem which had constantly to be borne in mind. Dr. Rivers shows, among other things, that certain peoples are unable to distinguish between the darker shades of colour, but that it does not necessarily follow when we find in a particular language one word for green and blue that those who speak that language have a colour sense in a state of low development. Dr. Rivers drew attention to the Celtic word glas. In Scottish Gaelic it signifies, as a colour term, grey, green and blue. But glas was originally something more than a colour term. Professor [[Author:W. J. Watson|W. J. Watson] of the University of Edinburgh has drawn my attention to the fact that it was used to denote vigour, as in Gàidheal glas (the "vigorous fresh Gael"), and water, as in Duglas ("dark stream") and Finglas ("white stream"). The original symbolism of the term is further emphasised when we find Tacitus stating that the Baltic people of Celtic speech who searched for amber referred to it as glese, and Pliny that the Germans called it glessum, a word Latinized from gless or glass.[1] Glas was thus in early times applied to water and magical products of water which were supposed to be impregnated with "life substance." In Scotland amber was believed to be generated by sea-froth continually dashed against the rocks.[2] It thus had origin like Aphrodite. The Baltic amber-searchers were worshippers of the mother goddess,
