TRAVELLER'S TREE 



supposed to have 700,000 leaves, must apparently have given 

 off into the atmosphere during five months 230,000 lb. of 

 water. 



Sometimes the water is so abundant in the plant that it 

 collects as drops on the tips of the leaves and falls off as 

 fluid water. A very young greenhouse plant (Caladium 

 nymphaefolium) was found by Molisch to give off 190 water- 

 drops a minute, and in one night it exuded one-seventeenth 

 of a pint. 



The water is found stored up in the stems or leaves of 

 plants, especially those of hot or dry climates. The Mada- 

 gascar Traveller's Tree, Ravenala, has a considerable amount 

 of water in a hollow at the base of its leaf, and it is possible 

 to drink this water. The usual story is to the effect that 

 a panting traveller finds this palm in the middle of the 

 desert, and saves his life by quenching his thirst with its 

 crystal-clear water. Unfortunately the tree never grows far 

 from marshy ground or springs, and the water, which I tasted 

 for curiosity, had an unpleasant vegetable taste, with 

 reminiscences of bygone insect life. 



These are, of course, exceptional cases ; as a rule the tiny 

 root-hairs search and explore the soil ; the sap or ascending 

 current passes up the stem and pours out into the atmo- 

 sphere. There the vapour is hurried off by winds, and 

 eventually condenses and, falling as snow or rain on the earth, 

 again sinks down into the soil. 



It is very difficult to understand how the sap or water rises 

 in the trunks of tall trees ; we know that along the path of 

 the sap inside, the root-hairs and other cells in the root, the 

 various cells in the stem, and finally those of the leaf, are all 

 kept supplied and distended or swollen out with water. All 

 these living cells seem to have the power of absorbing or 



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