EFFECTS OF NOTCHING 171 



growth has taken place, the organ, whether originally weak 

 or strong of constitution, is stimulated to the greatest 

 activity through the energetic up ward -pushing root-sap, 

 and the result of this is, by fall, a wood branch of luxu- 

 rious development. 



"A pronounced notch in very old wood calls forth either 

 a very rank twig or is without effect. In these cases, it is 

 evidently caused by the absence of a bud or a location for 

 one. If untoward conditions of nutrition are present, it 

 may possibly be due to a defective storage of the necessary 

 reserve materials. This latter supposition it might be diffi- 

 cult to prove. 



" The freezing of buds can call forth similar results on the 

 youngest wood, as those just described for old wood on 

 which there are, in general, no buds able to grow. On 

 many plants the buds suffer sooner than the cambium layer 

 of the wood. This is less noticeable on orchard wood than 

 on many natural woods; on the latter, in spite of the 

 strongest flow of sap, the sprouts will be missed under 

 such circumstances. 



w The notchings spoken of in the foregoing paragraphs have 

 great importance to the fruit-grower, partly in the shaping 

 of the tree and partly in the production of a balance in 

 the branching (or clothing) of t-he scaffold limbs of dwarf 

 orchard trees. But the notches above a bud into the bark, 

 and under a bud into the wood, cannot attain any impor- 

 tance in practice. 



" From what is known about the circulation and effect of 

 the sap, it may follow with some degree of clearness that 

 a notch above a bud, which removes but the bark and bast 

 layers, must tend to enfeeble and prevent sprouting, be- 

 cause the upward -moving sap is not stopped at the bud, and 

 the products of assimilation, which are a surplus from the 

 leaves, are withheld from the bud as long as the wound is 

 open. Many practical experiments with this notch gave^ 

 however, chiefly two results. In most cases no marked 



