Water Supply 



nothing enters or leaves the plant unless it is dis- 

 solved in water ; water is the vehicle by which all 

 substances (except the air in the spaces between the 

 cells) is conveyed from place to place, and even the 

 oxygen and the carbonic-acid gas are brought into 

 contact with the hving stuff dissolved in water ; 

 and water is one cf the necessary raw materials for 

 food-making. 



To obtain the most light and to get rid of as much 

 water as is necessary or as the plant can afiford, are 

 the problems which face every plant in the deter- 

 mination of its leaf structure, and many and wonder- 

 ful are the devices for meeting the two different ends, 

 the one demanding a large surface, the other often 

 rendering a contracted one absolutely essential. 

 Contrivances for getting rid of enough but not too 

 much water determine more than anything else the 

 form and habits of a plant. It is not too much to 

 say that it is possible to teU more about the con- 

 ditions under which a plant should be cultivated 

 (except as regards the temperature) by a con- 

 sideration of its foliage than by anything else, and 

 the most successful plantsman will be he who best 

 fits conditions, by choice of compost, regulation of 

 atmospheric moisture, and use of the water-pot and 

 other means of regulating soil-moisture, to suit the 

 water requirements of his charges. There are more 

 plants murdered by injudicious use of the water- 

 pot than by any other means, and there is no better 



15 



