lOG THE WORLD OF LIFE 



most equable regions of the earth. This is indicated by the 

 fact that about one-fourth of the natural orders of plants are 

 either exclusively tropical or very nearly so, and that they 

 comprise such remarkable forms as the epiphytic Orchids, the 

 Bromelias, the Palms, the Pitcher-plants, Bananas, Bread- 

 fruits, the Coffea and Cinchona trees, and hundreds of others 

 almost unknown except to botanists. 



But the most striking feature of all is the wonderful adapta- 

 tions by which every w^ell-marked place or station is occupied 

 by peculiar groups of plants. The epiphytes above referred to 

 • — plants which live upon trees, upon the trunks or branches, 

 and especially in the forks, where they can root and establish 

 themselves, not as parasites by sending their roots into the 

 living tissues of the tree, but solely getting nourishment from 

 the rain-water that trickles down the bark or the small quan- 

 tity of decaying leaves or moss that collects there — such 

 plants belong to many natural orders and are very numerous. 

 Then there are the climbers, far more abundant than in any 

 temperate forests, which either root in the ground and then, 

 by various means, climb up to the summits of the loftiest 

 trees, or which begin life by rooting in a lofty fork of a gi-eat 

 tree, and then send down roots to the ground and branches 

 into the air, sometimes remaining as a small bush or tree, at 

 others growing so rapidly above, and clinging around the sup- 

 porting tree so closely with its roots, as finally to kill its foster- 

 parent, when its clinging roots unite and grow into a trunk, 

 with hardly anything to show that one tree has replaced an- 

 other. Then again there are numerous small trees of from 20 

 to 30 feet high, which live entirely in the shade beneath the 

 great forest trees. Many of these have bright-coloured or con- 

 spicuous flowers growing directly out of the trunk, while there 

 are none at all among the crown of leaves at the top. This ap- 

 pears to be an adaptation to bring the flowers within sight of 

 the butterflies, bees, and other insects which fly near the 

 ground, and thus secure for them the advantages of being 

 cross-fertilised. Then again there are many delicate creeping 



