In each case, he holds, all the circumstances of the case must be examined and considered. For instance, when the Australians tell a myth about the Pleiades very like the Greek myth of the Pleiades, we must ask a number of questions. Is the Australian version authentic? Can the people who told it have heard it from a European? If these questions are answered so as to make it apparent that the Australian Pleiad myth is of genuine native origin, we need not fly to the conclusion that the Australians are a lost and forlorn branch of the Aryan race. Two other hypotheses present themselves. First, the human species is of unknown antiquity. In the moderate allowance of 250,000 years, there is time for stories to have wandered all round the world, as the Aggry beads of Ashanti have probably crossed the continent from Egypt, as the Asiatic jade (if Asiatic it be) has arrived in Swiss lake-dwellings, as an African trade-cowry is said to have been found in a Cornish barrow, as an Indian Ocean shell has been discovered in a prehistoric bone-cave in Poland. This slow filtration of tales is not absolutely out of the question. Two causes would especially help to transmit myths. The first is slavery and slave-stealing, the second is the habit of capturing brides from alien stocks, and the law which forbids marriage with a woman of a man's own family. Slaves and captured brides would bring their native legends among alien peoples. But there is another possible way of explaining the resemblance (granting that it is proved) of the Greek and Australian Pleiad myth. The object of both myths is to account for the grouping and other phenomena of the constellations. May not similar explanatory stories have occurred to the ancestors of the Australians, and to the ancestors of the Greeks, however remote their home, while they were still in the savage condition? The best way to investigate this point is to collect all known savage and civilised stellar myths, and see what points they have in common. If they all agree in character, though the Greek tales are full of grace, while those of the Australians or Brazilians are rude enough, we may plausibly account for the similarity of myths, as we accounted for the similarity of flint arrow-heads. The myths, like the arrow-heads, resemble each other because they were originally framed to meet the same needs out of the same material. In the case of the arrow-heads, the need was for something hard, heavy, and sharp--the material was flint. In the case of the myths, the need was to explain certain phenomena--the material (so to speak) was an early state of the human mind, to which all objects seemed equally endowed with human personality, and to which no metamorphosis appeared impossible.