5IO PRINCIPLES OF STRATIGRAPHY 



Kampar. It has a width of 12 kilometers and an area of more 

 than 80,000 hectares, and is covered by trees rising mostly to a 

 height of 30 m. It contains a peat deposit which has been sounded to 

 a depth of 9 meters. This peat consists largely of decayed woody 

 tissue. The larger roots of trees, with their upward pointing pneu- 

 matophores, form a solid basis in this swamp, which makes tra- 

 versing possible. The numerous varieties of trees have mostly slen- 

 der stems, bearing only a small crown of leaves, but with broad, 

 buttressed roots rising three to four meters above the ground, and 

 with remarkable aerial roots projecting in bundles for a meter or a 

 meter and a half from the trunk. Gymnosperms and monocotyl-, 

 edons are wholly wanting among the taller trees of this swamp, 

 these being chiefly composed of dicotyledons. Among the smaller 

 trees and bushes monocotyledons occur, though sparingly. Tree 

 palms are rare, but bushes of this family abound, especially several 

 species of a small Calamus. A small tree fern (Alsophila?) was 

 also found scatteringly. The herbaceous vegetation is sparingly rep- 

 resented both in species and individuals. Grasses and sedges are 

 practically wanting, the ground between the trees, where not occu- 

 pied by the aerial roots or ''knees," being strewn with decaying 

 leaves. Sphagnum is wholly wanting, and other mosses, liverworts, 

 lichens and herbaceous Pterydophytes are rare. Epiphytes occur 

 only in the leafy crown of the trees on account of the smooth char- 

 acter of their trunks. Phanerogamous water plants appear to be 

 rare, but thread-like algae were found to be numerous where the 

 forest was lightened through uprooting of trees by the winds. To- 

 ward the margin of this tropical swamp the vegetation gradually 

 changes, merging into that of the surrounding drier land. ( Potonie- 

 32.) 



Fossil Humuliths. 



The Humuliths of former geological periods are represented by 

 the following types : 



Lignite, 

 Brown Coal, 

 Bituminous Coal, 

 Anthracite, 

 Graphite. 



Lignite is wood, especially that of coniferous trees, which is in 

 its early stages of alteration, but still shows the woody characters 

 in unmistakable manner. Lignites are found in Mesozoic deposits 



