At the time when rock-shelters became favorite habitations of the people at the fire-cave, marriage relations were still loose, and any idea of male parentage was yet to come, but in a few generations, instead of accepting the birth of children without thought, it was generally believed that the supernatural beings with whom their imaginations peopled the hills, valleys, groves and ravines, were responsible for their advent. However, the more frequent and intimate association of the sexes around the fires and in preparing food by roasting, had a great effect, and it was noticeable that men and women began to pair off in the caves and rock-shelters; that such cohabitation continued for longer periods of time, and there were a number who appeared to have formed permanent unions. There was something about the fire--the social hearthstone--which tended to prolong such associations. The cheerful light of the fires; the measure of comfort they furnished, and the talkativeness promoted by companionship as the hunters related around the evening fires the adventures and experiences of that and former days, all combined to make man more of a social being, and the same influences promoted more permanency of union between couples who found themselves at all congenial. Perhaps the example of Longhead and Broken Tooth, who had remained true to each other, had something to do with this gradual change in the relations of the sexes, but it was not until many generations after when the fact of male parentage became known to mankind, that anything at all like marriage was known or any man regarded any child or children as his own. There being no settled custom in this matter, many couples continued to unite and separate as they might feel inclined. The most that can be said is, that the use of fire in some manner appeared to promote a longer union than was common before its discovery, and that, in the progress of ages, fire seems to have been one of the agencies which greatly assisted in bringing about the present sacredness of home and marriage. The hunters of the group still continued their coöperative search for food, and the fact that it was often impossible to determine who had killed a particular animal, while it was frequently certain that the weapons and efforts of several had a part in it, brought about a system for making an equitable distribution of all the animals taken in each expedition. First the share required by Longhead and Broken Tooth would be set apart, then the remainder was apportioned to each member of the group or to each habitation in proportion to the number of persons to be supported.