There are three of these forms of movement. They all fall within the historical period, and consequently we have some definite information about them. They may be designated as invasion, conquest, and colonization. These, with immigration, all have this in common, that they are reasoned movements arising after man had progressed far enough in the scale of civilization to have a fixed abiding place. That is, they are definite movements from one place to another. This distinguishes them from what has been called “wandering,” and justifies including them in a separate category, to which the general name “migration” may be given. In using this term for this purpose, however, we must rid our minds of the association which it has with the movements of animals and birds. When we speak of the migrations of birds we customarily refer to seasonal changes of location, occurring regularly year by year. They are not cases of a change of home, but of having two homes at the same time. Man, too, has his seasonal movements. It is a very common practice of primitive men to move from one location to another at different times in the year in the pursuit of food, seeking a certain locality at the time that a particular fruit ripens there, or a certain bird lays its eggs. “The Haida Indians of British Columbia annually voyage as many as 500 miles southward to Puget Sound to lay in a supply of dried clams and oysters for their own consumption and for trade.”[1] Many nomadic tribes follow the pasture from the lowlands to the highlands, and from south to north, as the seasons change. Even civilized man, in his highest development, has his seasonal journeyings, from his summer home to his winter home, and back. But none of these comings and goings deserve to be included as true movements of peoples, or to be called migrations in the present sense. Migration involves an actual and permanent change of residence. It thus becomes evident that migrations can occur only in the most rudimentary form among people in the hunting stage; more developed cases may occur among pastoral people, when they change their base of operation, as when the Israelites moved from Canaan into Egypt, and back after several generations; but in its most complete form, migration appears only after man has reached the agricultural stage.