282 SCIENCE PROGRESS 



will germinate in the ground under favourable conditions and 

 eventually develop into a tree ; the other by throwing up from 

 the roots or the base of the stem shoots or suckers which 

 develop into new trunks capable of supplying the place of the 

 original stem when it decays. When the first is followed, the 

 tree produced is a new individual and in the case of cultivated 

 fruit-trees differs materially from the parent tree or trees, 

 generally showing a strong tendency to revert to the original 

 uncultivated type of its ancestors ; in the second case, the new 

 tree is really part of the parent and is, in consequence, similar to 

 it in every respect. Most of our cultivated fruit-trees, however, 

 show very little tendency to send up suckers from their roots ; 

 similarly, when a twig or young branch is cut from them and 

 planted, this will very rarely root itself and become a tree : 

 consequently other means of multiplying individuals of any 

 particular variety of fruit-tree have to be adopted. The method 

 usually followed, as is well known, is to ingraft a bud or a 

 shoot of the tree required on to some young fruit-tree or 

 " stock," as it is called, already established in the ground ; 

 when the bud or buds develop, they reproduce all the main 

 characteristics of the tree from which they were taken, the 

 roots of the stock serving only as a means of conducting 

 moisture and food from the ground to the tree. Yet the character 

 of the root-stock is not entirely without influence on the growth 

 arising from the bud and according as a low-growing bushy tree 

 or a tall growing standard tree is required different root- 

 stocks possessing corresponding characteristics are used. For 

 growing bush-apples and pears, the paradise (pomme de paradis) 

 and quince stocks, respectively, are used, as these readily form 

 a mass of fibrous roots which stretch out only a short distance 

 below the surface of the soil ; whereas for standard trees the 

 root-stock used is the crab or pear stock, consisting of young 

 trees obtained by sowing pips of the crab-apple or pear. The 

 roots formed by these latter are comparatively few in number 

 but are stronger and penetrate deeper into the soil than those 

 of the dwarfing stock. The general character of the roots of 

 these stock will be evident from the accompanying illustrations. 

 Such stocks, budded or grafted with cultivated varieties of 

 apples or pears, form the " worked " trees which are planted 

 out from one to four years later to form orchards or fruit- 

 gardens. 



