422 The Philippine Journal of Science isu 



of bizarre plants and that their appearance is almost entirely 

 different from that of temperate ones. The low, mossy type of 

 high mountains is certainly very different from anything seen 

 in temperate countries. The tall dipterocarp type of forest, 

 however, presents an appearance strikingly similar to a deciduous 

 forest of the temperate zones; it differs from the latter largely 

 in having the trees arranged in stories, with an accompanying 

 greater density of foliage, and especially in containing a much 

 larger number of different species (Plate I, fig. 1). In the 

 best-developed dipterocarp forests the top story forms a very 

 even canopy, reaches to a height of about 65 meters or more, 

 and is composed almost entirely of dipterocarps (Plate V). The 

 trees frequently have a diameter of 1.5 meters and sometimes 

 2.5 meters or more (Plate VII) . In more poorly developed types 

 this story is lower and may contain more trees of other species 

 than of dipterocarps, while the canopy is frequently very irreg- 

 ular, as the dipterocarps are still the predominant large trees 

 and tend to tower over the other species. 



Under the top story there are two other stories, each composed 

 of distinct trees, and a ground covering of small bushes or herbs 

 (Plate VI, fig. 2). The presence of these three stories of dif- 

 ferent trees is not evident on casual observation, for the compo- 

 sition of all of the stories is very complex and few of the trees 

 present any striking peculiarities, while smaller trees of a higher 

 story always occur in a lower story and between the different 

 stories. The development of the lower layers is usually in in- 

 verse ratio to that of the top story, the reason being that the 

 better the top story is developed the less light passes through 

 to the lower stories (compare Plate I, fig. 2, and Plate II, fig. 1). 

 The middle story is composed of fair-sized trees which spread 

 their leaves under the branches of those of the top story. The 

 trees of the third or lowest story are small, about 10 to 12 meters 

 high, and have a relatively small amount of foliage (Plate VI, 

 fig. 2). Tree palms probably occur in all of the dipterocarp 

 forests of the Philippines, and may exceptionally form a con- 

 spicuous part of the vegetation in small pockets (Plate II, fig. 2). 

 In the best types they are usually relatively inconsiderable parts 

 of the vegetation. 



Climbing palms (rattans) (Plate VI, fig. 2) are always present 

 in large numbers, although they are much more prominent in 

 the poorer than in the best types of forest. The rattan plant 

 forms a rosette when young, and maintains this form until the 

 spiny, pinnate leaves are from 2 to 3 meters long. After this 

 it sends out a climbing stem with long internodes, and may 



