29 
Prosapiia are, together with Pliymaiodes, strongly represented ])ere. 
With the exception of P. ccespitosum and Thayeria, wliioh are epiphytes 
where Cheirophuria is terrestrial, the epiphytic vegetation is, like the 
terrestrial^ well scattered through the forest. 
The rain forest as a whole, as compared with the high forest, has two 
notable features not 3'ct mentioned in treating their divisions. The first 
is the larger proportion of epiphytes, 53 per cent in comparison with 
45 per cent. The reasons for this are evident. The more luxuriant 
vegetation puts a greater premium on the better illuminntion of the 
epiphytes and the greater and more con'^tnnt humidity removes part of 
the difficulty of the epiphytic habit. The other notable feature of the 
rain forest flora is the strong representation of isolated, new, or sup- 
posedly rare species and genera and of small genera. Tliis peculiarity 
is doubtless in part merely apparent, due to our greater ignorance of the 
rain forest in comparison with our knowledge of the high forest in otiicr 
places; but in larger part it is real and explical)le. The rain forest, 
jii>t as is locally tlie case at San Ramon, in all this part of the world 
occupies a small area as compared with the high forest; it is therefore 
less likely to develop large genera adapted to its conditions. More impor- 
tant than this, the rain forest is in small areas, often very isolated, and 
the uplands are the oldest and longest isolated situations of every part 
of the globe. Under such conditions, isolated types of vegetation are 
bound to occur. The most notable illustrations are Schkostege and 
TJiayeria. Others, aside from species elsewhere unknown, are AntropJi- 
yum latifoUurrij Cheiropleuria, Microlepia hirsuta, Monogramma and 
Lomagramma. 
THE MOSSY FOREST. 
The mossy forest is the one in which the extreme humidity })ermits 
such a luxuriance of epiphytes that they stunt the growth of the trees. 
Such a condition is most readily reached where strong light acts together 
with moisture to favor the epiphytes, — that is, on ridges nnd peaks — and 
in such places the exposure to wind is another powerful factor in 
dwarfing the trees. However, at an altitude of near 6,000 feet on Apo 
a sheltered plateau exists, with a moist and suflRoient soil. The trees 
in this place are not notably dwarfed in height— they are not high- 
growing species— but the development of their branches and foliage is 
very weak. The most abundant tree here, as is u=ual elsewhere on ridges 
in the mossy forest, is Lrpfn<:pe.rm7i7n amhoinense. The ground in this 
situation is cold; it was somewhat below 15° C. at the place where I 
camped in April and October. This coldness, and the mantle of epiphy- 
tes on the stems and even on the leaves, check the development of the 
trees, even though no high winds aid in bringing about this condition. 
The mossy forest may or may not be elfln-wood, and elfin-wood may or 
may not be mossy. 
