The Natchez produced the artificial form by bandaging the infant’s head to a well-cushioned cradle-board by means of strips of deer-skin.[265] The Caribs bandaged the head with pieces of wool, and gave it a very quadrangular shape. The Choctaws produced artificial compression by means of a bag of sand.[266] The unintentional flattening of the skull arose from the quite general use of the cradle-board without any board for pressure, or the custom common among many American tribes of the mother suckling the child over her shoulder, a practice widely prevalent in Africa and among savage nations. In the former instance it is but reasonable to suppose that the form of a tender and pliable skull would be modified more or less by the shape of the hard cradle-board, and by the position in which it was placed upon its rest. This fact accounts for the slight occipital compression of the mound skulls and also for the irregularity of the flattening in many cases. The latter process, that of nursing the child from its position on the shoulder or back would no doubt subject the head to a slight pressure, perhaps in most cases in a lateral direction. The general prevalence of the unnatural custom of flattening the skull on the eastern border-land of Europe and among the numerous tribes of the western coast of America, together with its presence in Polynesia as a connecting link, we think justifies us in concluding that it originated among the wild hordes of the northern steppes of Asia, from which centre it spread in lines of radiation until it reached the remote localities in which recent research has found it.[267] This fact is suggestive of a remote intercourse between peoples separated by seas and mountains, if it does not serve as an argument for the unity and common origin of the human family.