The Pochteca were careful to set out on their expeditions on a favourable day, such as 1. coatl, and before starting they made offerings to their god and the Earth; they also cut their hair and washed their heads, since custom forbade them to do either while on a journey. Their relations were also obliged to remain with head and face unwashed, except at intervals of eighty days, during their absence. They started out in a large body, merchants from various towns combining to form a caravan, as far as Tochtepec. There they divided, some going to Anauac Ayotlan, others to Anauac Xicalanco (southern Vera Cruz and Tabasco). When they returned, often after years of absence, they awaited a favourable day to enter their city, such as 1. calli, or 7. calli, when their home-coming was celebrated by a banquet and various religious ceremonies. Each merchant carried a staff, which was regarded as the image of the god Yacatecutli, and received offerings in his name. When on the march, the company of merchants at night tied their staves together, and offered incense before them, at the same time making blood-offerings from their ears and tongues. The extraordinary facility with which nomadic hunting tribes adopt a trading profession has many parallels in Africa, where the interests of the wandering merchant are similarly guarded. Just as violence against one of the Pochteca inevitably resulted in a punitive expedition, so in times past the murder of a Bushongo trader by a Basongo Meno village would result in the extermination of the latter, and, at the present day, the death of a Badjok merchant would be similarly avenged by his compatriots. Mexican trade was for the most part carried on by means of direct exchange, and the result provides many difficulties to the archæologist. Once a town became famous for any kind of manufacture, the work of its artisans became spread far and wide, so that the discovery of objects of a particular style in a certain locality can by no means be taken necessarily to indicate that that style is characteristic of the site. Even pottery, which provides such valuable evidence in other parts, is not exempt from suspicion, since the ware of Cholula constituted an important article of export from that town. Certain articles formed a rough-and-ready currency in commerce, such as textiles and maize; cacao beans also were used as a kind of “small change,” and copper axe-blades were employed in certain localities, such as Oaxaca. More than one of the contemporary historians mention quills containing gold-dust as being utilized for the same purpose. The great market in Tlaltelolco moved the wonder of the conquerors; it is described as being three times as large as that of Salamanca, and one estimate places the daily attendance at twenty or twenty-five thousand persons. One of the conquerors gives the following picture of it. “On one side are the people who sell gold; near them are they who trade in