The Scioto and the Ohio valleys, it may be presumed, were the seats of separate states, with frontier populations living in part on the produce of the chase; but depending largely on agricultural industry for the sustenance of the communities crowded on the flats and river-valleys where their monuments abound, and for the supply of the workmen by whose combined labour they were constructed. The religious character and uses ascribed to one important class of their earthworks, in which scientific skill is most clearly manifested, points to the probable existence of a sacerdotal order, such as played an important part in the polity both of Mexico and Peru. There is indeed so great a discrepancy between the remarkable combination of science and skill in the execution of the Ohio earthworks, and the crude state of the arts otherwise associated with them, as to suggest the idea of a sacerdotal caste, like the Brahmins of India, distinct in race, and superior in intellectual acquirements to the great mass of the people. Of the physical characteristics of the Mound-Builders, notwithstanding the ransacking of many sepulchral mounds, we possess as yet very partial evidence. This department of the subject will come under review in a subsequent chapter; and it will then be seen that while the accepted Mound-Builders’ type of head has been largely based on the very specimen selected by Dr. Morton, as “the perfect type of Indian conformation,” with its undoubted traces of compression, and of the use of the cradle-board, so characteristic of the Indian hunter: it seems not improbable that a systematic exploration of the mounds may disclose evidence of a ruling class differing physically as well as intellectually from the mass of the community by whose toil the enduring monuments of their singular rites and customs have been perpetuated.