ANIMAL AND PLANT INTELLIGENCE 



and implies a nervous system. It is thought by 

 some that the roots of a water-loving plant divine 

 the water from afar and run toward it. The truth 

 is, the plant or tree sends its roots in all directions, 

 but those on the side of the water find the ground 

 moister in that direction and their growth is accel- 

 erated, while the others are checked by the dryness 

 of the soil. An ash tree stood on a rocky slope 

 where the soil is thin and poor, twenty or twenty- 

 five feet from my garden. After a while it sent so 

 many roots down into the garden, and so robbed 

 the garden vegetables of the fertilizers, that we cut 

 the roots off and dug a trench to keep the tree from 

 sending more. Now the gardener thought the tree 

 divined the rich pasturage down below there and 

 reached for it accordingly. The truth is, I suppose, 

 that the roots on that side found a little more and 

 better soil, and so pushed on till they reached the 

 garden, where they were at once so well fed that 

 they multiplied and extended themselves rapidly. 

 Both plant and tree know a good thing when they 

 find it. How could they continue if they did not ? 

 A birch tree starting life upon the top of a rock, 

 — as birch trees more than any others are wont 

 to do, — where the soil is thin, soon starts a root 

 down to the ground several feet below in what seems 

 a very intelligent way. Now the tree cannot know 

 that the ground is there within reach. On one side 

 of the rock, usually on the north side, it finds 

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