CONTRIBUTIONS TO PHYSIOGRAPHY OF PHILIPPINES. 21 



We left part of the force behind at Camp Clinton and then proceeded 

 up the valley^ making halts as indicated on the accompanying route 

 sketch. At the foot of the mountain proper, our force again was 

 divided and one company took the trail over the pass and down the 

 the long eastern slope to Camp Stotzenburg on the Pampanga side. 

 The remaining company with us marched to the next water hole and 

 then likewise separated, one part remaining below with the superfluous 

 baggage and arms. Here a select number of men were chosen and we 

 began one of the hardest pieces of mountain climbing I have engaged in 

 in the Philippine Islands. From the 915 meters' elevation up to about 

 1,535 meters the trail leads over an exceedingly rocky slope where great 

 care must be taken not to dislodge loose stones and bowlders and hurl 

 them upon the party following. 



The Negrito guides easily outdistanced us in this part of the climb. 

 At 1,535 meters we entered the heavy growth of timber and small vegeta- 

 tion which so persistently clings about the summits of the majority of 

 high mountains in the Tropics. The botanist calls this the mossy forest. 

 as it is marked by a great profusion of moss covered trees. 



The white men of the party kept with the Negritos after entering 

 the forest, and one or two made even better headway. Although the 

 trees are somewhat stunted on the summit of the mountain, the vegeta- 

 tion is very dense and this, together with the haze, prevented our having 

 a very clear view over the surrounding country. 



PHTSIOGEAPHT OF THE AGLAO VALLEY. 



The Aglao Valley presents a physiographic puzzle which to me at 

 least has been almost inexplicable. A cross section of it about midway 

 in its length is given in the accompanying map. This figure shows that 

 the valley consists of two chief parts, an upper portion wide, flat- 

 bottomed, and with moderately steep walls, and a second and lower part, 

 a deep gorge with exceedingly straight walls, narrow and rather more 

 V-shaped at the bottom. 



The gorge shows that the valley filling is of loose material, sand, and 

 bowlders. As these gorges are in places, from 30 to 45 meters deep we 

 can count on the filling extending to at least that depth, and if we 

 continue the natural slopes of the valley walls downward so as to re- 

 construct the preexisting valley, we get some idea of the probable 

 amount of fill, which must be in the neighborhood of 120 to 150 meters 

 in depth. 



The floor of the upper valley is strewn with immense bowlders, some 

 of them many tons in weight. They possess a remarkable similarity to 

 a valley train in glaciated countries. In certain portions of the valley 

 there are gorges smaller than the large one which follows more nearly 



