by necessity, would eventually be pursued for its own sake; and not a few would be found who would investigate, and, as far as they could, record the various phenomena they observed. The paintings of Egypt and the sculptures of Assyria are our witnesses of the skill with which animals and plants were drawn, and of the minute perception of their external forms; and the knowledge thus gained in the ancient centres of civilization would be sure to circulate and increase when the intercourse with foreign nations spread the knowledge and philosophy so acquired.
In the writings of Homer we find that the knowledge of the anatomy of the human body had already made considerable progress; and the inspection of the animals offered in sacrifice cannot fail to have added much to the general knowledge of their history. A century later, we have the poems of Hesiod, devoted to the encouragement of agriculture and rural pursuits. Pythagoras, in the seventh century B.C., may perhaps have left no writings, but we know that he was an eminent student and exponent of natural phenomena. His contemporary, Alcma3on of Crotona, is especially mentioned by Aristotle; and he is eminent among natural philosophers as the first who is said to have recommended to his followers the practice of dissection. Empedocles of Agrigentum left a work on the phenomena of nature, of which a few fragments still remain, and there were also others who, if they did not enter into the details of what we now call natural history, treated generally of the nature of things, and opened the field to those who would study the subject in its particular parts. The empire of Persia was still the dominant power, and was carrying the civilization of the East to every part of the known world when Ctesias wrote his great works, of which, unhappily, only a few fragments remain. He described not
