In 1908 Metchnikoff received the Nobel Prize, together with Ehrlich, for his researches on immunity. According to the statutes of that prize, the laureate is invited to give a lecture in Stockholm. Metchnikoff chose for his theme the "present state of the question of immunity in infectious diseases," and, in the spring of 1909, we went to Sweden and thence to Russia. The whole journey was a series of fêtes and receptions in his honour. He was touched and grateful at this welcome, but with his usual humour, declared that it was the Nobel Prize which, like a magic wand, had revealed to the public the value of his researches. We only stopped for a short time at Stockholm, where the kindest hospitality was shown to Metchnikoff. Sweden made an unforgettable impression upon us. Her deep, dark waters, wild rocks, and sombre pines make of it a land of legends. Elie was impressed not only by Nature in Scandinavia but also by Scandinavian Art, which reproduces it admirably. He was specially pleased with Lilienfiorse's pictures, representing animals against a background at the same time real and legendary. We went to Russia by way of the Baltic. The nights at that time were "white," and rocky islands covered with pines emerged from the sea like ghosts, in the mysterious silvery midnight light; the impression was fairy-like. A warm welcome awaited Metchnikoff in Russia. At Petersburg, as in Moscow, he was received with cordial and enthusiastic sympathy not only by scientific and medical societies, but by all the intellectual youth of those cities. This warm reception contributed to efface the bitterness sometimes aroused in him by distant recollections of the reasons which caused him to leave his native country. During our stay in Russia we made the acquaintance of our great writer, Léon Tolstoï. We spent a day with him in his estate, Iasnaïa Paliana, and the day left a lifelong impression upon us. It was at dawn that we reached the little railway station where a carriage had come to meet us. It had been raining in the night and now, in the first morning light, everything shone with dew. We were excited by the sight of the Russian country, cool meadows, forest, fields, all that simple landscape that we had not seen for so long, and we were also greatly moved at the idea of meeting Tolstoï. The village appeared in the distance and, a little way apart, the wide open entrance gate of the old park of Iasnaïa Paliana. We entered a long shady avenue leading to the home of Tolstoï. The spring was at its best, flowers and perfumes everywhere. The house and the old park had the poetic charm of the ancient "nests of nobility" in Russia.