'To begin with the underworld river the Cocytus: Plato describes it and the region where it forms a lake as being dark or a deep dark blue in colour: the colour of kyanos ... Etymologically, 'Cocytus' is the river of mourning and tears, and this is how the name was understood by the Greeks down to the end of antiquity; but at the same time we happen to know that in Greek literature and religion the coulour of kyanos was itself, par excellence a colour of mourning. The precision and aptness in Plato's choice of adjective are impressive, and rather too great to be no more than a coincidence. Once again it is difficult not to be struck by how little of the details in the myth is arbitrary, out of place, or meaningless. But this too is not all. The colour of kyanos appears to have had a special connection with the mysteries of Demeter and Persephone and--through the cult of the two goddesses--with water and the underworld ... The spring at Syracuse where Hades is said by tradition to have snatched Persephone down into the underworld was called, precisely, Kyane; and here too, exactly the same ambiguity or spead of meanings applies as the one just noted above. Plainly there is a reference in the name of the spring to the colour of its water. But at the same time, in relation to the mysteries of Persephone and Demeter the colour of kyanos has very dfinite associations with mourning, and the choice of the name for the spring is undoubtedly related to the annual rites of mourning performed beside it in honour of Demeter's lamentation and tears over the loss of her daughter Persephone.