22 THE WANDERINGS OF ANIMALS [OH. 



gorgeous orchids, bromelias and other epiphytes, the 

 seeds or spores of which have started many feet above 

 the ground, so that these plants never know the ground 

 proper. They were born aloft, have grown aloft 

 generation after generation until they have forgotten 

 what it was like to grow up from the bottom, and 

 thus they have become epiphytes or even parasites. 

 Many of these, though never the primary supporting 

 trees themselves, have ingenious methods for con- 

 ducting, collecting and storing the rainwater ; either 

 all their leaves form a nest-like whorl, as is the 

 fashion of some Bromelias and Tillandsias ; or, may 

 be, one leaf is turned into a scroll. 



A striking feature of such a tropical forest is that 

 it is composed of an astonishing number of different 

 genera and species of trees, forming the greatest 

 possible mixture, while continuous groves of one 

 kind are rarely met with. Whilst the temperate 

 region has extensive oak, beech and pine forests, no 

 such uniformity exists in the tropical belt unless we 

 ascend into the mountains. There is a cause for this 

 variety. The exuberance of life is so great, and 

 therefore the struggle for individual existence is so 

 severe that there is little chance for two trees of the 

 same kind to succeed in growing up side by side. 

 It is almost by a lucky accident that one grows up at 

 all where hundreds of other plants want to do the 

 same. 



