254 PHYSIOLOGY OF TREES. 



said to be the depositories of the matured sap 

 sent down by the foliage. A potatoe, for in- 

 stance, contains a decided store of this organi- 

 sable matter : but divest this tuber of its gems or 

 eyes, it instantly becomes a caput mortuwn ; this 

 concentrated body of organisable hfe becomes 

 inert, and quickly submits to putrefaction. 



One of the principal arguments in support of 

 this strange doctrine is drawn from the circum- 

 stance, that a fruit tree, in high vigour, is less 

 fruitful than one of a moderate or even weakly 

 growth ; and if this vigorous tree receive a check, 

 it almost immediately becomes prolific. This, it 

 is said, is occasioned by the sap, in consequence 

 of its stagnation, becoming eminently mature, 

 and expended in the formation of flowers and 

 fruit, instead of being rapidly wasted in the 

 production of wood. But the fact is, flow^ers 

 and fruit are not so expeditiously formed as this 

 supposition would lead us to believe ; they have 

 existence in the shoot long prior to their appear- 

 ance on its exterior. The rapid growth of a 

 shoot is not by an evolution of its central parts, 



