GRAFTACK CENERAr, (\IX SI DICRATK IXS 



145^ 



FIG. 130— TWO YEAR 

 SPY BUDDED TREES 



A, stem cut at 15 inches 

 and grafted, B, Uncut. 

 This shows that top- 

 working checks growth. 

 It also delays bearing. 



the larger continuous air- 

 1t ilding vessels and the walls 

 of whose cells are often 

 thickened and lignified. The 

 xylem is separated from the 

 phloem (20"2) by tlie cam- 

 hiuni, when there is any. and 

 it usually occupies the side 

 of the bundle toward the 

 center of the stem. \\'ater 

 with the mineral compounds 

 in solution passes up 

 through the xylem to the 

 lea^"es. 



204. Limits of graftage. 

 Theoretically botanists and 

 nurserymen have limited 

 graftage to the exogens, 

 plants which have a cam- 

 bium layer in a definite re- 

 gion beneath a bark layer; 

 for the process depends upon 

 the intimate union of 



it is alwa)'s sharply defined from the 

 remaining portion (xylcni, 2().'i ) ])y a 

 layer of cambium. The mner bark is 

 derived from the phloem, the wood 

 from the xylem. The elaborated plant 

 food from the leaves passes down and 

 is distributed by the phloem. 



203. Xylem, or woody portion of a 

 fibro- vascular bundle which contains 



FIG. 131— BURLAPPED FOR 

 SHIPMENT 



Trees so handled have usually been 

 + i_i- 1'^T/ii- K.^+iTToon ^*.^ 1 ^^°^ pruned for two or more years to 

 tnis Id} Cr IJCt^\een stock have large bunches of short fibrous roots. 



and Cion. Of the 151 ^reat'ed!'^ ^""°'' '"' '° ^'°" *''" ^° 



