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with the mass of half-decayed organic material of the beech or maple 
forests which is so prominent in some places in temperate regions, the 
Lamao soil is poor. The intermediate stage between the forest litter and 
the almost completely disintegrated organic matter is passed over quickly 
in the Tropics. This, perhaps, will account for the impression that the 
humus accumulation is not great. It must be remembered that the forces 
which bring about the decomposition of complex organic compounds, 
both of plants and animals, are much stronger in the Tropics, and because 
of the continuous warmth they are continually at work. Thus there is no 
accumulation of organic, decaying matter in the intermediate stages. In 
temperate regions, on the other hand, the accumulation during the whole 
year is greater than can be disposed of during the short, warm period in 
which nitrifying bacteria and other agents of decay would be operative ; 
consequently, each year a surplus is added to the constantly increasing 
mass. In regions of great rainfall, where during heavy rainstorms the 
surface becomes a sheet of water, a great deal of organic litter is washed 
into the streams and thus lost to the forest. Especially is this the case 
in regions of rough topography, where the drainage is excellent. 
Correlated with the scarcity of half-decomposed organic matter is a 
rather scanty development of fleshy fungi, though at the beginning of 
the rainy season a number of forms appear. Woody fungi, however, are 
constantly in evidence, usually on old logs or standing dead trunks. 
Among the genera present may be mentioned Awricularia, Schizophyllum, 
Sterum, Polystichus, Polyporus, Fomes, and Trametes. Mosses and 
liverworts are scantily represented. Lichens are found abundantly on 
the smooth bark of the trees and on boulders. Other than the crustaceous 
forms are almost entirely absent. 
Many of the ecological and structural characteristics of the Anisoptera- 
Strombosia formation are also present in the other formation, so that a 
repetition of this matter will not be necessary. However, where differ- 
ences occur, attention will be called to them. It has been noted that in the 
Bambusa-Parkia formation many -xerophytic and tropophytie structures 
appear. In the Anisoptera-Strombosia formation the same condition is 
obtained, but to a less extent. The evergreen element is much more 
pronounced and the deciduous nature correspondingly less characteristic. 
This is in accord with the more mesophytic conditions which prevail here 
in contrast with the lower formation. However, as shown by the tables, 
many plants prevail in both habitats. Trees like Parkia, Lagerstremia, 
and Ficus with a partial deciduous habit are present, though less con- 
spicuous in the Anisoptera-Strombosia than in the Bambusa-Parkia 
formation. 
Summary.—l. In the Anisoptera-Strombosia formation a two-story 
vegetation prevails; the bamboo story of the Bambusa-Parkia forest is 
replaced by small dicotyledinous trees represented by Strombosia. 
