The Story-Book of the Fields 



brightly coloured, round or long, hard or 

 mellow — all these pears ripened on the same 

 tree and were reproduced year after year 

 unaltered, true to the racial character, not 

 of the supporting tree, but of the different 

 shoots grafted on to the common stock. 



The association of similar plants will not 

 insure the success of the operation. There 

 must be abundant contact between the graft 

 and the stock in their most vital parts, which 

 are the most capable of uniting. This con- 

 tact must take place in the interior layers of 

 the bark, and in the new substances situated 

 between this and the wood ; for it is in this 

 region that the life of the plant is most active. 

 The mature sap descends between the bark 

 and the wood, where new cells and new fibres 

 are organised, forming a sheet of bark on 

 one side and a layer of wood on the other. 

 It is only in this part that the union between 

 the graft and stock can be effected. 



198 



