CLIMBING AND WATER PLANTS 109 



upwards, along or through the supporting 

 vegetation, only produces minute leaves, and 

 at very distant intervals. It is ,not until the 

 roof of the forest is reached tnat the large 

 crop of big green leaves is unfolded, and their 

 weight is entirely borne by the vegetation 

 over which they are growing and spreading. 

 Entangled as the climber becomes among the 

 branches of the sustaining trees, it is evident 

 that when the latter are swayed by the wind, 

 the danger of snapping which confronts its 

 thin stems is a very real one. Furthermore, 

 while the plant is a young one, the risk of 

 being parted from the root is not small. These 

 difficulties are all obviated in several ways. 



In many of them the first formed wood of 

 the young plant consists almost entirely of 

 strong mechanical tissue, and this is especially 

 true of those climbers which produce no 

 functional leaves worth mentioning till they 

 reach the roof of the jungle. The presence of 

 this axile cord of sclerenchymatous wood is 

 most important to all these plants, for they 

 need to be very flexible, and at the same 

 time to be able to withstand very considerable 

 pulls which might otherwise snap them 

 asunder. The fact that they are admirably 

 constructed in these respects is illustrated by 

 the name of " jungle ropes," by which so 

 many of them are commonly known a 

 popular tribute to their flexibility and their 

 very great strength. 



But it is evident that stems constructed 



