tropic jungle and on the other with sturdy pine trees; at the crest line the children of the Tropics meet and intermingle with those of the temperate zone.  There are gigantic, rolling, bare backs whose only covering is the carpet of grass periodically green and brown.  There are long, rambling, skeleton ranges with here and there pine forests gradually creeping up the sides to the crests.  There are solitary volcanoes, now extinct, standing like things purposely let alone when nature humbled the surrounding earth.  There are sculptured lime rocks, cities of them, with gray hovels and mansions and cathedrals.

The mountains present one interesting geologic feature.  The “hiker” is repeatedly delighted to find his trail passing quite easily from one peak or ascent to another over a natural connecting embankment.  On either side of this connecting ridge is the head of a deep, steep-walled canyon; the ridge is only a few hundred feet broad at base, and only half a dozen to twenty feet wide at the top.  These ridges invariably have the appearance of being composed of soft earth, and not of rock.  They are appreciated by the primitive man, who takes advantage of them as of bridges.

The mountains are well watered; the summits of most of the mountains have perpetual springs of pure, cool waters.  On the very tops of some there are occasional perpetual water holes ranging from 10 to 100 feet across.  These holes have neither surface outlet nor inlet; there are two such within two hours of Bontoc pueblo.  They are the favorite wallowing places of the carabao, the so-called “water buffalo,"[6] both the wild and the half-domesticated animals.

The mountain streams are generally in deep gorges winding in and out between the sharp folds of the mountains.  Their beds are strewn with bowlders, often of immense size, which have withstood the wearing of waters and storms.  During the rainy season the streams racing between the bases of two mountain ridges are maddened torrents.  Some streams, born and fed on the very peaks, tumble 100, 500, even 1,500 feet over precipices, landing white as snow in the merciless torrent at the mountain base.  During the dry season the rivers are fordable at frequent intervals, but during the rainy season, beginning in the Cordillera Central in June and lasting well through October, even the natives hesitate often for a week at a time to cross them.

The absence of lakes is noteworthy in the mountain country of northern Luzon —­ in fact, in all of northern Luzon.  The two large lakes frequently shown on maps of Cagayan Province, one east and one west of the Rio Grande de Cagayan near the eighteenth parallel, are not known to exist, though it is probable there is some foundation for the Spaniards’ belief in the existence of at least the eastern one.  In the bottom land of the Rio Grande de Cagayan, about six hours west of Cabagan Nuevo, near the provincial border of Cagayan and Isabela, there were a hundred