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the bark, and spread at right angles to the stem. Some of the 

 smaller species have leaves less than an inch long, and the larger 

 ones are four to six inches long. Species of Piper are also low 

 climbers with a somewhat similar habit, but with more spreading 

 leaves. 



Next in size are the aroids, with many different species. They 

 are root climbers, but the large leaves are produced in great num- 

 bers and may completely hide the trunk of the supporting tree. 

 A climbing bamboo, SchizostacJiyiim, is also very common. It 

 produces a dense but loose tangle of stems, which may double 

 the apparent diameter of the supporting tree, and the small 

 leaves are produced freely over the whole mass. A larger bam- 

 boo, Dinochloa, has rather solitary stems. These smaller lianas, 

 Pothos, Piper, Schizostachyum, and the aroids, represent the 

 shade-loving species. While it is frequently considered that 

 the liana habit may have developed in response to a demand for 

 greater light within the forest, it is obvious that it has developed 

 to a variable degree, because to these smaller species the amount 

 of light available is certainly not very different from that received 

 by plants of normal stature on the ground. Just how much that 

 is, is not definitely known, but in photographing them the neces- 

 sary exposure is one hundred to three hundred times as great 

 as would be required in the open. Whether these shade-loving 

 forms have developed from shade-loving ancestors, or from 

 larger sun-loving lianas, is a question of considerable interest to 

 the ecologist. 



The larger lianas all differ from these in having long leafless 

 stems, with the foliage developed only at a great height, where 

 it can compete for light with the leaves of the trees which sup- 

 port them. Of course they must begin their development on 

 the ground, and there may be a very long and severe struggle 

 for existence before they finally attain the requisite freight. Just 

 how large these plants may be is again a question, because in 

 several trips on the slopes of Mt. Makiling the writer was never 

 able, even with the aid of a field glass, to recognize with certainty 

 the foliage of any particular liana from that of the trees around 

 it. It is probable that their development is favored by the 



