In Ireland in the late 18th century, peasants carrying sticks went house-to-house on Samhain collecting food for the feast. Charles Vallancey wrote that they demanded this in the name of St Colm Cille, asking people to "lay aside the fatted calf, and to bring forth the black sheep". In parts of southern Ireland during the 19th century, the guisers included a hobby horse known as the Láir Bhán (white mare). A man covered in a white sheet and carrying a decorated horse skull would lead a group of youths, blowing on cow horns, from farm to farm. At each they recited verses, some of which "savoured strongly of paganism", and the farmer was expected to donate food. If the farmer donated food he could expect good fortune from the 'Muck Olla'; not doing so would bring misfortune. This is akin to the Mari Lwyd (grey mare) procession in Wales, which takes place at Midwinter. In Wales the white horse is often seen as an omen of death. Elsewhere in Europe, costumes, mumming and hobby horses were part of other yearly festivals. However, in the Celtic-speaking regions they were "particularly appropriate to a night upon which supernatural beings were said to be abroad and could be imitated or warded off by human wanderers". Hutton writes: "When imitating malignant spirits it was a very short step from guising to playing pranks". Playing pranks at Samhain is recorded in the Scottish Highlands as far back as 1736 and was also common in Ireland, which led to Samhain being nicknamed "Mischief Night" in some parts. Wearing costumes at Halloween spread to England in the 20th century, as did the custom of playing pranks, though there had been mumming at other festivals. At the time of mass transatlantic Irish and Scottish immigration, which popularised Halloween in North America, Halloween in Ireland and Scotland had a strong tradition of guising and pranks. Trick-or-treating may have come from the custom of going door-to-door collecting food for Samhain feasts, fuel for Samhain bonfires and/or offerings for the aos sí. Alternatively, it may have come from the Allhallowtide custom of collecting soul cakes. The "traditional illumination for guisers or pranksters abroad on the night in some places was provided by turnips or mangel wurzels, hollowed out to act as lanterns and often carved with grotesque faces". They were also set on windowsills. By those who made them, the lanterns