PRUNING THE ORCHARD. 



and may for present purposes be considered 

 as simply the branched extension of the 

 stem underg-round. The cambium of the 

 stem is continuous with that of the root, 

 and is covered and protected with bark, ex- 



cept at the growing points. The covering- 

 of bark, being as was said before, impervi- 

 ous to moisture, requires that all water ab- 

 sorbed by the plant under normal conditions, 

 be taken in at the root tips. In order to 

 facilitate the easy and speedy passage of 

 moisture into the plant, we have the small 

 hair-like bodies known as root-hairs. 



Root-Hairs. — Root-hairs may best be 

 seen on some seedling plants such as beans. 



Fig 2222. — Oak tree from which some of the 

 lower limbs have been properly cut and most of 

 the upper ones improperly cut. (By permission 

 from U. S. Year Book of Agriculture, 1895.) 



i* iG. 2^23, — Decay caused by the cutting of too 

 large a limb, (By permission from U. S. Year 

 Book of Agriculture, 1895.) 



