ON THE ACTION OF WATER ON PLANTS. 129 



ing from their appearrance of age and decrepitude. The 

 stems, so curiously split asunder, look as if they bid defi- 

 ance to the violence they have suffered ; and, twisting the 

 dismembered remnants of their stems together, seem to 

 verify jEsop's fable of the bundle of sticks, and acquire 

 additional vigor to withstand the attacks of time and of 

 the elements. 



CONVERSATION X. 



ON THE ACTION OF WATER ON PLANTS. 



Mrs. B. WATER may be considered as acting on plants 

 in several different ways : the first and most important of 

 which is, its being the vehicle of their nourishment. The 

 greater the quantity of nutritive particles which water 

 contains the more favorable it is to vegetation, unless it 

 should be so far saturated as to be too dense to pass 

 through the pores of the spongioles. In that case the 

 plant is reduced to the state of Tantalus, and perishes of 

 famine in the midst of plenty. 



We have already observed, that, of three particles of 

 water which enter a plant, one only remains within it ; 

 and this either retains its natural liquid state, analogous 

 to the water of crystallisation in minerals, or is decompos- 

 ed, to contribute to the formation of oils or other peculiar 

 juices of vegetables. 



In the second place, water acts mechanically on plants, 

 by dilating them, and rendering them supple. The 

 woody fibre absorbs water abundantly, but not the bark. 

 The former is often so swelled by this absorption as to 

 burst and split the bark. 



Caroline This is no doubt one of the causes of the 

 roughness of the bark of many trees, such as the oak and 

 the elm, which are so seamed and severed into small parts. 



Mrs. B. Yes ; these, in the course of time, dry and 

 fall off. In other trees the bark remains smooth, but 

 peels off when split by the swelling of the wood. 



719. In what proportion is water favorable to vegetation! 720. 

 What is said of the one particle of water out of the three which enter a 

 plant, which continues to remain in itl 721. What is the second way 

 in which water acts upon plants'? 722. How does this sometimes 

 cause the bark to burst! 



