Had the bison remained for a few more centuries in undisturbed possession of his range, and with liberty to roam at will over the North American continent, it is almost certain that several distinctly recognizable varieties would have been produced. The buffalo of the hot regions in the extreme south would have become a short-haired animal like the gaur of India and the African buffalo. The individuals inhabiting the extreme north, in the vicinity of Great Slave Lake, for example, would have developed still longer hair, and taken on more of the dense hairyness of the musk ox. In the "wood" or "mountain buffalo" we already have a distinct foreshadowing of the changes which would have taken place in the individuals which made their permanent residence upon rugged mountains. It would be an easy matter to fill a volume with facts relating to the geographical distribution of _Bison americanus_ and the dates of its occurrence and disappearance in the multitude of different localities embraced within the immense area it once inhabited. The capricious shiftings of certain sections of the great herds, whereby large areas which for many years had been utterly unvisited by buffaloes suddenly became overrun by them, could be followed up indefinitely, but to little purpose. In order to avoid wearying the reader with a mass of dates and references, the map accompanying this paper has been prepared to show at a glance the approximate dates at which the bison finally disappeared from the various sections of its habitat. In some cases the date given is coincident with the death of the last buffalo known to have been killed in a given State or Territory; in others, where records are meager, the date given is the nearest approximation, based on existing records. In the preparation of this map I have drawn liberally from Mr. J. A. Allen's admirable monograph of "The American Bison," in which the author has brought together, with great labor and invariable accuracy, a vast amount of historical data bearing upon this subject. In this connection I take great pleasure in acknowledging my indebtedness to Professor Allen's work. While it is inexpedient to include here all the facts that might be recorded with reference to the discovery, existence, and ultimate extinction of the bison in the various portions of its former habitat, it is yet worth while to sketch briefly the extreme limits of its range. In doing this, our starting point will be the Atlantic slope east of the Alleghanies, and the reader will do well to refer to the large map.