Embracing as they do almost the whole field of Greek myth and legend, the subjects on Greek vases are yet not invariably those most familiar to the classical student or, if the stories are familiar, they are not always treated in accordance with literary tradition. On the other hand, it must be borne in mind that the popular conception of Greek mythology is not always a correct one, for which fact the formerly invariable system of approaching Greek ideas through the Latin is mainly responsible. The mythology of our classical dictionaries and school-books is largely based on Ovid and the later Roman compilers, such as Hyginus, and gives the stories in a complete connected form, regarding all classical authorities as of equal value, and ignoring the fact that many myths are of gradual growth and only crystallised at a late period, while others belong to a relatively recent date in ancient history.[13] The vases, on the other hand, are contemporary documents, free from later euhemerism and pedantry, and presenting the myths as the Athenian craftsmen knew them in the popular folk-lore and religious observances of their day. It cannot be too strongly insisted upon that a vase-painter was never an illustrator of Homer or any other writer, at least before the fourth century B.C. (see Vol. I. p. 499). The epic poems, of course, contributed largely to the popular acquaintance with ancient legends, and offered suggestions of which the painter was glad to avail himself; but he did not, therefore, feel bound to adhere to his text. This will be seen in the list of Homeric subjects given below (p. 126 ff.); and we may also refer here to the practice of giving fanciful names to figures, which obtains at all periods, and has before now presented obstacles to the interpreter.