somewhat gradual introduction of trade placed these deadly weapons in the hands of some tribes, and of whole congeries of tribes, long before others could obtain them.  Thus the general state of tribal equilibrium which had before prevailed was rudely disturbed.  Tribal warfare, which hitherto had been attended with inconsiderable loss of life and slight territorial changes, was now made terribly destructive, and the territorial possessions of whole groups of tribes were augmented at the expense of those less fortunate.  The horse made wanderers of many tribes which there is sufficient evidence to show were formerly nearly sedentary.  Firearms enforced migration and caused wholesale changes in the habitats of tribes, which, in the natural order of events, it would have taken many centuries to produce.  The changes resulting from these combined agencies, great as they were, are, however, slight in comparison with the tremendous effects of the wholesale occupancy of Indian territory by Europeans.  As the acquisition of territory by the settlers went on, a wave of migration from east to west was inaugurated which affected tribes far remote from the point of disturbance, ever forcing them within narrower and narrower bounds, and, as time went on, producing greater and greater changes throughout the entire country.

So much of the radical change in tribal habitats as took place in the area remote from European settlements, mainly west of the Mississippi, is chiefly unrecorded, save imperfectly in Indian tradition, and is chiefly to be inferred from linguistic evidence and from the few facts in our possession.  As, however, the most important of these changes occurred after, and as a result of, European occupancy, they are noted in history, and thus the map really gives a better idea of the pristine or prehistoric habitat of the tribes than at first might be thought possible.

Before speaking of the method of establishing the boundary lines between the linguistic families, as they appear upon the map, the nature of the Indian claim to land and the manner and extent of its occupation should be clearly set forth.

Population.

As the question of the Indian population of the country has a direct bearing upon the extent to which the land was actually occupied, a few words on the subject will be introduced here, particularly as the area included in the linguistic map is so covered with color that it may convey a false impression of the density of the Indian population.  As a result of an investigation of the subject of the early Indian population, Col.  Mallery long ago arrived at the conclusion that their settlements were not numerous, and that the population, as compared with the enormous territory occupied, was extremely small.[1]

    [Footnote 1:  Proc.  Am.  Ass.  Adv.  Science, 1877, vol. 26.]

Careful examination since the publication of the above tends to corroborate the soundness of the conclusions there first formulated.  The subject may be set forth as follows: