Trade by barter followed seizure by raids. But a long period of piracy intervened between the early practices of silent barter and the later trade by modern exchange methods. A fetish was used to stand guard over the deposits of goods for silent barter. Such market places were secure against theft; nothing would be removed except by barter or purchase; with a fetish on guard the goods were always safe. 
Never did the barter in sex slaves advance society; such traffic was and is a racial disgrace, for at one and the same time it hindered the development of family life and polluted the biologic fitness of superior peoples.