In conclusion, one may note that regularities are found in Banisteriopsis drink experiences between tribes as widespread as the Choco Indians west of the Andes in Colombia and the Tacana Indians east of the Andes in Bolivia. However, all of these Banisteriopsis-using peoples occupy a tropical forest environment and their cultures often share much in content. Given the relative contiguity as well as the environmental and cultural similarities of these tribes, it seems virtually impossible to isolate the nature of the yage-induced experience from its cultural context on the basis of these ethnographic data alone. Comparative material, such as the following paper by Naranjo, may eventually help contribute to a gradual solution of this problem.