WATER AS AN AGRICULTURAL AGENT. 365 



This fluid called sap or juice, runs through the whole structure 

 of the plant, carrying with it all the constituents of vegetable 

 growth. In this stream of water are dissolved the carbon, nitrogen, 

 potash, phosphates, with other elements or compounds of food de- 

 manded by the growing plant. 



Vegetation, by an unknown process, takes out of tlie sap the 

 carbonic acid, atnmonia, and various salts, leaving the water to be 

 thrown off by the leaves — for, says Prof. Johnson, "we have no 

 proof of a downward flow of sap." If food is thus conveyed into 

 the vegetable body, why may it not be carried in the same way 

 into the animal body ? The natural laws which govern both are 

 similar, if not identical. The boundaries of the two great king- 

 doms of plants and animals tread closely upon one another. Says 

 a writer, " there is a closer aflinity between the animals and vege- 

 table organism than most of us are willing to admit," whether we 

 regard the theory of Darwin as tenable or untenable. 



" We know that plants as well as animals eat; that they breathe, 

 perspire, and are sensitive to the touch. We know that they have 

 sexes, and a circulatory apparatus ; that they sleep, although, 

 unlike the sluggard, the first raj's of the morning light awakens 

 them, to join, it may be, although their voices are inaudible to the 

 human ear, the songs of thanksgiving and praise that resound 

 from the feathered vocalists. They send their messages of love 

 through the ambient air that they perfume with many odors, em- 

 ploying the busy bee, which becomes the Cupid in the dominions 

 of Flora and Pomona, inviting willing mates to connubial felicity, 

 and thus they, too, 'multiply, replenish, and adorn the earth.' " 



Plants have, strictly speaking, no bony system, no stomachs, 

 no digestive apparatus, no heart nor lungs, like animals, to propel 

 and to aerate circulating fluid. Every plant which grows is made 

 up of little cells, each cell having its especial life. These cells, 

 similar to the compartments of a honey-comb, are filled with fluid. 

 They are so small that in a cubic inch of wood there are often 

 more than a million. These cells perform the offices of the stomach 

 in the plant, receiving the fluid of which there is a constant influx 

 from the roots. Tlie digestion of plants may be due to chemical 

 action, more wonderful than the force which produced an Andes 

 or a Niagara, ever at work, obstructing those substances brought 

 up in the sap, and applying them, by cell multiplication, to the 

 growth of the plant. The food supplied to the plant is in a state 

 of solution when absorbed by the roots, while, of the food con- 



