The title, _The North Americans of Yesterday_, seems to me appropriate, because while there are still some Amerinds extant, and a few are even yet apparently leading the old-time life, nevertheless they are merely remnants of a people whose sun has set, and who therefore properly belong to yesterday. For this reason I have mainly treated them as a bygone race. Between the so-called “Red Indian” of the United States and northern regions and the so-called “Civilised Tribes” of Mexico and southern regions I have made no race differentiation, because the differences, whatever they may be, are discovered to be not of kind, but of degree. Confusion was formerly caused by misconceptions and by romantic ideas which have been dispelled by the more scientific methods of later days. Some confusion has been caused also by the persistent efforts to classify the progress of mankind as a whole into distinct world-epochs or time periods. It seems to me that no such universal epochs of even progress could have existed in past time any more than in present time. Tribes of men are differentiated now, always will be, and, I believe, always have been. Common world-planes of culture in time periods are an impossibility. Such schedules as Morgan’s may apply to tribes and stocks as indicating their special, individual advance, but not to the whole world, except in a very general way. That is, they may be _culture_ but never _time_ classifications. The closer we approach the beginnings of man’s existence, the less marked, perhaps, the differences in tribes, but differences certainly began at the moment when one group of men left another group of men to live apart. The environment and necessities of each group would cause differences and varying rates of progress. One group would gain the bow a thousand years before another.