Through this grand valley as a door one goes into the Cajon proper. The river is bordered with thick foliage, and gigantic cliffs rise like coulisses, one behind another, away up, in the most varied colors of the quaternary rock, alternating with lava. The pillar-shaped Pitabaya fastens itself in the clefts of the steepest, even vertical cliffs. Rarely wider than half a mile, yet affording by its numerous bendings a constant change of view, never bare, but unceasingly grand and wild, the ravine appears to go along with the traveller, till the solitary palm-tree at the entrance to the half-ruined city of Arispe introduces him to a new and entirely different landscape: a hollow verdant with fields and with poplars; in the east the Sierra Arispe rises bare and forbidding; the west bank descends steeply to the river's edge, and to it clings a group of adobe dwellings with many ruins of stone buildings and a large, bare church. This is the former capital of Sonora, the population of which has diminished by two thirds in half a century a melancholy place of decay in the lead region. Here the Rio de Bacanuchi empties into the Sonora from the north, and the Sonora turns; between Bacuachi and Arispe it flows from northeast to southwest. I have already observed that Guagarispa most probably stood on the site of the present Arispe. No ruins of it are visible; they have been built over; but stone axes, mortars, and grinding stones (metates) are unearthed here and there. A ravine like that between this place and Sinoquipe begins on the Sonora River farther north, and at "Ti-ji-só-ri-chi" stand above the river the ruins of an ancient pueblo. The coun-