498 SMITH. 



into consideration, it is quite possible that Matutan will be found to bo 

 appreciably higher than Apo. No record, so far as I Imow, of an 

 ascent of the former exists. 



Mount Apo shows a circular depression suggestive of a crater at 

 the top and, although the rock is igneous and gases issue from a great 

 fissure in the side of the mountain, I would not, in the strictest sense, 

 term it a volcano for the following reasons : 



1. There are neither ashes nor signs of lava outpourings; the rock on this part 

 of the mountain is rather more holoerystalline than effusives usually are. 



2. The "crater," as it apparently shows no signs of the products of vulcanism 

 about it, might be explained as a water erosion cirque ; this question will be 

 discussed more at length in the paper on the geology of Mindanao. 



3. The structure of the mountain is schistose due to pressure and shows clearly 

 that this is a structural peak. Plate XX shows this sehistosity and its anticlinal 

 course. 



The morning temperature at the summit was 8° C. A small lake 

 exists on a shoulder of the mountain, apparently about 500 meters below 

 the summit ; it was not visited. The return to Davao occupied two days. 

 Here I left the expedition to return to Manila, and Messrs. Goodman and 

 Ickis continued the reconnaissance from Davao to Surigao by way of 

 the Agusan River. 



