tongues at Babel, or by the early and long-continued separation of different tribes. The point, however, now to be urged, is this. Such naturalists as Agassiz, on merely zoölogical principles, have decided that it is more probable (not that it is necessary or certain, but simply that it is more probable), that the different varieties of men, even down to different nations, have had different origins, and as Agassiz in his later writings maintains, are of different species; when, in many cases at