THE River of the title is the Pasión-SalinasLacantún-Usumacinta system of the Petén, which is the southern interior portion of the Yucatán peninsula, an immense region of tropic jungle. What ostensibly drew Mr. Halle to it was the Ruins of his title— the ruins of the Mayan culture as found in Tikal, Yaxchilán, Piedras Negras, Palenque, and other anciently flourishing centres of population. These, with one congenial fellow student, he visited, partly to investigate and to photograph, but even more just ‘to journey through space and time, to gaze upon the lost features of another civilization, and there to behold the great dragon of eld, the primeval wilderness that had returned in the fullness of its strength to triumph upon the ruins’; also to muse without distraction upon the mortality of even the most potent and prosperous civilizations. The majority of the pages are given to the incidents and means of travel and to description of birds and animals, natives and settlers, rivers, savannas, weathers, and above all the teeming jungle itself. Thought is interpenetrated with humor, humor with thought, both with acute and disinterested observation. The writing is unobtrusively delightful, often distinguished. River of Ruins is, in fine, an engaging and in these times a thoroughly refreshing record of travel in space and time.