standing as a symbol of mother-love. Fabulous creatures, too, appear in these pages. Of the Phœnix, that bird whose plumage glitters with gold and precious stones, which was known even to Herodotus, and which has survived through Eastern fairy-tales on to the time of our own romanticists (Tieck), we read: 'it lives a thousand years, because it has not eaten of the tree of knowledge'; then 'it sets fire to itself and arises anew from its own ashes,' a symbol of nature's infinite power of renewing its youth. But while among the peoples of Europe all the science of the ancients was lost, except a few barely recognizable fragments, the old lore was preserved, both as regards organic nature and other orders of facts, among the Arabs, through whom so many treasures of antiquity have eventually been handed down to us, coming in the track of the Arabian conquests across North Africa and Spain to the nations of Europe. It was in this way, too, that the writings of Aristotle again found recognition, after having been translated into Latin at Palermo at the order of that enthusiast for Science and Art, the Hohenstaufen Emperor, Frederick the Second. Our Emperor presented one copy of Aristotle's writings to the University of Bologna, and thus the wisdom of the ancient Greeks again became the common property of European culture. From the thirteenth century to the eighteenth, the study of natural science was limited to repeating and extending the work of Aristotle. Nothing new, depending upon personal observation, was added, and it does not even seem to have occurred to any one to subject the statements of the Stagirite to any test, even when they concerned the most familiar objects. No one noticed the error which ascribed to the fly eight legs instead of six; there was in fact as yet no investigation, and all knowledge of natural history was purely scholastic, and gave absolute credence to the authority of the ancients.