Christmas things and customs comprise much that has great interest from a scientific point of view. Our modern celebration of Christmas in England is a combination of the Christian festival of the Nativity with that of the Epiphany, and that of St. Nicholas, who long ago was substituted for the sea god Neptune, of classical mythology, by sea-faring folk. Santa Claus--or Saint Nicholas--has his festival at the beginning of December, but he has been carried over to Christmas Day, and appears as “Father Christmas” in modern celebrations. There is no great antiquity about this part of the tradition which we try to keep alive at Christmas. The making of Christmas Day and Christmastide into a special children’s festival is, on the other hand, a moving back of the festival of the Epiphany, when gifts were brought to the child Christ by wise men of the East. In Rome I have assisted in celebrating our Twelfth Night under the name “Befani,” at a great illuminated public fair, near the Pantheon, where children are taken to buy toys. There has been in England also a similar moving back of the very ancient--even prehistoric--celebrations of the New Year to Christmas, and hence it is that the mysterious and sacred “mistletoe” of the Druids is mingled in our houses with the less significant but beautiful holly as a decoration. The Christian Church, however, did not, and does not, sanction the introduction of mistletoe into the sacred edifice, and not many years ago those who loved and truly understood tradition would not permit mistletoe to be mixed with holly even in the private house at Christmastide. Mistletoe, it was held, could not be rightly introduced until the new year. The new year, however, of the Druids differed in date from that of the later calendar, and fell in what is to us the second week of March. The holly tree, with its splendid red berries and shining, prickly leaves, is a beautiful decorative plant, very hardy and abundant: it was used by the old Romans in their “Saturnalia,” a feast which nearly coincided with the Christmas of the new religion. There is a species of holly in South America the leaves of which are made into tea by the Indians, the Paraguay tea or matté. This tea is an unpleasant, bitter decoction, devoid of aroma, if I may judge from samples which I have tasted in London. “Ilex” is the botanical name of the genus to which both our holly-tree and the Paraguay tea belong, but it must not be confused with the evergreen oak to which the name Quercus ilex is given on account of the resemblance of its leaves to those of a holly.