CH. rv. 



MISCELLANEOUS. 



113 



pended in the air by their branches : ' cut the stems 

 below the heads and eradicate them. The trmikless 

 heads on the wall, full of growth, leaves, and fruit, 

 would be curious and beautiful objects ! and the 

 absence of the roots below would be a great conve- 

 nience to the gardener ! 



We, indeed, see daily, in plashing thorn hedges, 

 how small a quantity of wood and bark is necessary to 

 form the connecting link between the head and the 

 root, and permanently to preserve vitality. But if Mr. 

 Wallis's facts are facts, we should see them every day ; 

 we should see the stems and branches of trees and 

 underwood, when cut, continue to grow, and their 

 roots die. But what we do see is the exact reverse of 

 this. 



Mr. Walhs alludes also to the fact, that trees when 



cut down will, sometimes shoot out in the next summer. 



This has been always known, and always accounted 



for by the elder physiologists as the effect of what 



they called the concrete sap previously stored in the 



tree. But as trees separated from their roots are 



separated from the source of their sap, these shoots 



never live after the first summer. 



As the roots of trees grow in length through the Best time 

 11 • • 1 • 1 1 trans- 



earth, they are m perfect contact with it, and as they pI^^^^^^^s 



increase each year in girthing this contact is continued, ^Jj^^^^ 



and the pressure against the earth even increased. I 



imagine that this close contact of the roots with the 



earth is very essential for the absorption of moisture ; 



I 



