348 



THE UNIVERSE. 



The identity between the organs is so complete that the 

 physiologist can even transform the middle part of the stem 

 into a root, whilst above and below this it puts out branches 

 covered with leaves, in such a manner that the tree thus 

 represents two trees placed one above the other. Duhamel 

 proved this by a curious experiment. He surrounded the 

 stem of a willow with a cask filled with earth, which was 

 raised from the ground to a higher level than the first 



branches of the tree. Adventi- 

 tious roots soon shot out on this 

 part of the trunk, while above and 

 below it was laden with boughs 

 covered with verdure. 



Anatomy assigns generally three 

 functions to the roots : they fix 

 the tree, feed it, and at the same 

 time fill the office of excreting 

 organs. 



In most of the Fuci the root 

 merely represents a sort of cramp- 

 Si ing iron, serving just to anchor 

 the plants at the bottom of the 



159. Adventitious Roots upon a Trunk. . 



Experiment. sea, without drawing the least 



particle of nourishment from the rock which it grasps. The 

 myriads of little claws by which the ivy attaches itself to 

 the rugged stone of tombs and walls seem also designed 

 solely to fix it to its favorite site. 



storm, and fell across a gully. The branches took root on the other side, and 

 from the parent stem, thus fed, shot up perpendicularly fifteen trees all in a row, 

 which still flourish in all their splendor. Science Gossip, 1865. TB. 



