RELATION OF MOUNTAINS TO SEA AND COSTAL PLAINS 525 



h. Naguilian Trail, from San Fernando to the Bagnio highland, north 

 central Lnzon. 



c. Tila Pass, tlirough the Malaya Eange into Lepanto subprovince. 



d. Balbalasan Trail, into the Kalinga highlands, northern Lnzon. 



e. Jnan Villaverde Trail, across tlie northwestern corner of Lnzon. 

 /. Infanta-Tanay Trail, across the rugged mountains east of Manila. 

 g. Atimonan Eoad, southeastern Luzon. 



li. Tabuk Trail, in southern Mindanao. 



In addition to these, there are many other shorter, but very important, 

 routes leading through the mountains in the smaller islands like Panay, 

 Cebu, etcetera. Some of the tribes make use of these passes, particularly 

 the lowland peoples, such as the Ilocanos, who go up into the highlands 

 to trade. But as far as the writer has had experience with the hill peo- 

 ples, they seem to pay little attention to topography in traveling, almost 

 invariably taking the shortest route, no matter how steep the trail may 

 be. Our method of following contours does not appeal to them on first 

 acquaintance. The lowland peoples do, however, pay some attention to 

 topography. For confirmation of these statements the reader is asked to 

 consult the census^ map, showing the distribution of the various tribes. 

 He will see at a glance how completely the paths of the Ilocanos, a coastal- 

 plain tribe, criss-cross the country of the Igorot along the lines of least 

 resistance — that is, by way of the lowest elevations. This also will help 

 to explain the spread of some of the other tribes, such as the Tagalogs, 

 from the region around Manila to the east coast of Luzon. 



Pkoximity of Mountains to Sea and coastal Plains 



As a consequence of the proximity of the mountains to the coasts, we 

 would expect to and do find that there is little or no development of 

 coastal plain, and that it is comparatively narrow where it does exist. 

 However, with the steady growth of the coral platforms all about the 

 coast' and the contemporaneous deposition of great volumes of debris 

 from the mountains, coastal plains are rapidly growing. The rainfall in 

 this region on one occasion was almost the record for the globe, being 39 

 inches in 24 hours, as recorded at the Baguio Observatory, July, 1911. 



The subject of torrential wash alone would furnish material for an ex- 

 tensive paper, but we can not digress at too many points in this paper. 

 Suffice it to say, that these tremendous downpours, which carry enormous 

 quantities of debris, profoundly afiect the life of the people in these 

 regions. 



Philippine Census, 1903, vol. i. 



