MESOPHYTE SOCIETIES. 



255 



straight leafless tree-trunks, so that the leaves of trees are 

 mainly clustered at the tops of high brandies. The shade 

 is so dense and the interference is so great that the devel- 

 opment of low branches is impossible. It is common, also 



Fig. 213 A -roup of aerial plants (epiphytes) from a tropical forest, Note the vari- 

 ous hahits of the epiphytes attached to the tree-trunks, and the dangling roots - 

 After Schimper. 



for the larger trees to develop a system of buttresses near 

 the base, and also frequently to send out prop roots (see 

 Figs. 100, 101). 



(5) Absence of hud scales.— In the deciduous forest bud 

 scales are necessary to protect the tender growing tips dur- 

 ing the period of cold. The same device would be suffi- 



