Anthropologists, who have been deeply interested in the controversy ranging round the origin of man, have in a remarkable manner neglected to take into full account the most significant phenomenon of spreading out.[293] They either neglect it altogether, or they relegate it to so small a place in their argument as to become a practical neglect. They treat of man as if he were always in a stationary condition, and exclude the important condition of movement as an element in his development. Mr. Spencer's general dictum that geological changes and meteorological changes, as well as the consequent changes of flora and fauna, must have been causing over all parts of the earth perpetual emigrations and immigrations,[294] does not help much, because it refers to special and cataclysmic events. Lord Avebury, though stating the true case, unfortunately contents himself at the end of his book on prehistoric man with a short summary of the evidence as to the equipment of primitive man in mental and social qualities when he began the great movement, and gives only a few lines to his conclusion that "there can be no doubt that he originally crept over the earth's surface little by little, year by year, just, for instance, as the weeds of Europe are now gradually but surely creeping over the surface of Australia."[295] Mr. Keane is the first authority who thinks it appropriate to commence his treatise on man with an examination of the facts which show that "the world was peopled by migration from one centre by pleistocene man ... who moved about like other migrating faunas, unconsciously, everywhere following the lines of least resistance, advancing or receding, and acting generally on blind impulse rather than of set purpose;"[296] and it still remains with Dr. Latham to have formulated some fixed principles of the migratory movement in his admirable though, of course, wholly inadequate summary of man and his migrations. I will quote the passage in full: "So long as any continental extremities of the earth's surface remained unoccupied--the stream (or rather the enlarging circle of migration) not having yet reached them--the _primary_ migration is going on; and when all have got their complement, the primary migration is over. During this primary migration, the relations of man, thus placed in movement and in the full, early and guiltless exercise of his high function of subduing the earth, are in conflict with physical obstacles and with the resistance of the lower animals only. Unless, like Lot's wife, he turn back upon the peopled parts behind him, he has no relations with his fellow-men--at least none arising out of the claim of previous occupancy. In other words, during the primary migration, the world that lay before our progenitors was either brute or inanimate. But before many generations have passed away, all becomes full to overflowing, so that men must enlarge their boundaries at the expense of their fellows. The migrations that now take place