CAUSES OF BARRENNESS, &C. 163 



no flowers, and consequently yield no fruit, while a 

 stunted, or even a sickly one, yield both abundantly ? 



How is it that a tree, a grape vine for instance, in 

 full vigour as to age, and previous fruitfulness, shall 

 suddenly become barren if removed from a higher to 

 a lower place in the vinery, though at the same time 

 its growth be accelerated ? 



Why are healthy shoots from the stem, or from the 

 crowded interior of a tree, always sterile, whilst those 

 of the exterior are prolific ? 



Before these questions can be answered, or the 

 answers understood, it will be necessary to consider 

 first the real nature of the connection between those 

 members which constitute the bulk of the plant and 

 the fructiferous gems contained therein. The former 

 are the annually increasing bodies of bark and wood ; 

 these are enlarged to a greater or lesser size, and in a 

 longer or shorter time by the favouring circumstances 

 of soil, situation, and season. The incipient fruit- 

 bearing gems are seated on the pith at the base of 

 every bud, whether lateral or terminal, of our common 

 fruit-trees ; but their development does not depend on 

 those circumstances which prompt and assist the 

 growth of the wood and bark, but on a stationary re- 

 pose in which their organisation is engrossed, matured, 

 and fitted for perfect and vigorous expansion, by the 

 influences of full air and light. The maturation and 

 development of the fructification are subdued by the 

 exuberant growth of the other constituents, whereby 

 that rest, or stationary existence is denied, and there- 



M '2 



