The Physiologus or Sacred Natural History.--During this period of crude fancy, with a fog of mysticism obscuring all phenomena of nature, there existed a peculiar kind of natural history that was produced under theological influence. The manuscripts in which this sacred natural history was embodied exist in various forms and in about a dozen languages of Eastern and Western Europe. The writings are known under the general title of the Physiologus, or the Bestiarius. This served for nearly a thousand years as the principal source of thought regarding natural history. It contains accounts of animals mentioned in the Bible and others of a purely mythical character. These are made to be symbolical of religious beliefs, and are often accompanied by quotations of texts and by moral reflections. The phoenix rising from its ashes typifies the resurrection of Christ. In reference to young lions, the _Physiologus_ says: "The lioness giveth birth to cubs which remain three days without life. Then cometh the lion, breatheth upon them, and bringeth them to life.... Thus it is that Jesus Christ during three days was deprived of life, but God the Father raised him gloriously." (Quoted from White, p. 35.) Besides forty or fifty common animals, the unicorn and the dragon of the Scriptures, and the fabled basilisk and phoenix of secular writings are described, and morals are drawn from the stories about them. Some of the accounts of animals, as the lion, the panther, the serpent, the weasel, etc., etc., are so curious that, if space permitted, it would be interesting to quote them; but that would keep us too long from following the rise of scientific natural history from this basis. For a long time the religious character of the contemplations of nature was emphasized and the prevalence of theological influence in natural history is shown in various titles, as Lesser's _Theology of Insects_, Swammerdam's _Biblia Naturæ_, Spallanzani's _Tracts_, etc. The zoölogy of the _Physiologus_ was of a much lower grade than any we know about among the ancients, and it is a curious fact that progress was made by returning to the natural history of fifteen centuries in the past. The translation of Aristotle's writings upon animals, and the disposition to read them, mark this advance. When, in the Middle Ages, the boundaries of interest began to be extended, it came like an entirely new discovery, to find in the writings of the ancients a storehouse of philosophic thought and a higher grade of learning than that of the period. The translation and recopying of the writers of classical antiquity was, therefore, an important step in the revival of learning. These writings were so much above the thought of the time that the belief was naturally created that the ancients had digested all learning, and they were pointed to as unfailing authorities in matters of science.