SOCIETY OF NORTHERN ILLINOIS. 369 



To continue the propagation of these half-hardy sorts by root- 

 grafting, wouUl seem to he utterly out of keeping with the spirit of 

 the times and the character of our people who, in every other occu- 

 pation, quickly discern any plan of operation that promises advance- 

 ment or progress. Can it be possible that the art of fruit-tree grow- 

 ing should be an exception to this rule, and that our farmers and 

 orchardists should have no better provision made for future plant- 

 ings than these half-hardy sorts, that have been weighed in the bal- 

 ance so nnmy years and found wanting. It seems to me that this 

 question has been abundantly agitated and discussed of late years to 

 open the eyes and the understanding of the most conservative 

 nurseryman in the northwest, and yet we have to listen occasionally 

 to the lamest arguments that could be imagined, which are defended 

 with a tenacity worthy of a better cause. For instance, some men will 

 ascribe the diificulty to an imagined deterioration of seeds and a 

 consequent enfeebled condition of the seedling roots used for graft- 

 ing. Others again ascribe it to the use of pieces of roots for that 

 purpose, and argue that the entire root should be used; some pre- 

 tend that budding on the collar is the only method by which hardy 

 trees can be produced; others advocate the use of the "blight 

 proof, ( ?) iron-clad, French crab root" is the only remedy. Enough 

 of these " hobbies," none of which can possibly effect the resisting 

 power of the stem, when this is composed of a tender or half-hardy 

 variety. 



As is well known, the stem or trunk of a tree is always subject 

 to a greater injury by severe cold or sudden changes of temperature, 

 than any other part of the tree. The reasons for this fact are ob- 

 vious. The stem being the conductor of sap between the root and top, 

 it necessarily receives any flow of sap forced up by the roots, and has 

 all its inter-cellular spaces between the cambium and bark completely 

 filled up before transmitting it into the branches. Then the ripen- 

 ing process, which commences in the top and proceeding downward, 

 the stem is the last past of the tree that is relieved of its excess of 

 water. Perfectly matured and healthy wood fiber contains about 

 forty per cent, of water, diffused in molecular combination with cel- 

 lular tissue and starch molecules. In this condition resistance to 

 cold is perfect. If, however, there is an excess of water present, as 

 is the case in immature wood, or iu the abnormal rising of sap dur- 

 ing protracted warm weather in winter, the tree being exposed to 

 cold weather, such water molecules are forced out from the cellular 

 tissue and arranged in layers of ice crystals between the bark and 

 cambium, or even between concentric rings of the wood fiber, caus- 

 ing a rupture of the bark and destruction of the inter-cellular tissue. 

 The degree of injury depends on the quantity of water present and 

 the degree of cold. As our entire assortment of the west European 

 type is subject to this difficulity, there is no other method of preven- 



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