IN the number of NATURE for November 17, Mr. John Jeremiah states that “Heol y Gwynt” is the only proper Welsh name for the Milky Way. Such is far from being the case. I am acquainted with no less than nine other names, equally proper for that luminous appearance, such as y llwybr llaethog, y ffordd laeth, llwybr y gwynt, galaeth, eirianrod, crygeidwen, caer Gwydion, llwybr Olwen, and llwybr y mab afradlawn. Of these names, y llwybr llaethog and y ffordd laeth answer precisely to Milky Way; llwybr y gwynt (common enough in Carmarthenshire) is synonymous with heol y gwynt; galaeth (from llaeth, milk) corresponds with galaxy; eirianrod signifies a bright circle; and crygeidwen a white cluster. To caer Gwydion (the mural enclosure of Gwydion) belongs a tale, which may be compared with the stories of classical antiquity on the same subject. Gwydion is a noted character in early Welsh romance, in which he figures as an astronomer and an enchanter. He was the son of Don, king of Llychlyn or Scandinavia, and is said to have lived in the fourth century. According to the Welsh poets, he travelled through the heavens in search of a lady, who had eloped with Gronwy Befr, and left a track behind him, which has ever since been called Caer Gwydion. When he found the faithless lady he changed her into an owl. His scientific acquirements are often mentioned in Welsh mythology, and frequent allusions are made to him as an enchanter by the early bards. He is said to have been instructed in magical arts by Math ab Mathonwy, and in the Mabinogi, or tale which bears the name of the latter, his achievements are detailed at length. According to some of the Welsh records he was buried at Morfa Dinlle, on the seashore near Carnarvon.