72 SEEDLING PROPAGATION OF VAKIETIES. 



strongly pictured, to represent the real advantages 

 derived from root and top pruning. The pruning of 

 the top should always be done before planting, as the 

 roots do not obtain sufficient hold of the soil to pre- 

 vent their being disturbed and pulled out by the 

 knife. 



INFLrEXCE OF THE GEAFT UPON LONGEVITY. 



The increase of the number of trees of a given variety 

 has for some years been considered as a simple exten- 

 sion of the original tree of that variety. Grafts or 

 buds taken from any variety of the Pear, when inserted 

 into a pear stock, will entirely change its character- 

 istics, and enforce the production of their own variety 

 of fruit. Having this power, it is not too much to 

 believe, that they have that also of carrying with them 

 whatever defect of constitution, or feebleness of vitality, 

 may infect the plant, and that trees produced from 

 them would be feeble or strong, short or long-lived, in 

 proportion to the possession or want of these qualities 

 in the original. 



That the defects of a tree must limit the powers of 

 all its descendants, is a well known physiological fact. 

 But the different trees of a variety are not descendants 

 from an original of that variety, but only parts of it ; 

 and starting from this basis, some pomologists have 

 asserted, tliat as all the trees of any variety are but 

 branches from the original, and not the product of 

 fecundated seed, they must be limited in their exist- 

 ance by the life of the original. 



In this theory, however, sufficient allowance is not 

 made for the increase of vitality, 1)y alliance with 



