1 34 FLOWER-GARDENING. 



which the sap flows in its passage from the roots into the 

 leaves. 



81. In exogenous stems (63) it certainly rises through the 

 alburnum, and descends through the bark. 



82. In endogenous stems (64) it probably rises through the 

 bundles of wood, and descends through the cellular substance ; 

 but this is uncertain. 



83. Stems have the power of propagating an individual only 

 by means of their LEAF-BUDS. If destitute of leaf-buds, they 

 have no power of multiplication, except fortuitously. 



IV. LEAF-BUDS. 



84. Leaf-buds are rudiments of branches, inclosed within 

 scales, which are imperfectly formed leaves. 



85. All the leaf-buds upon the same branch are constitution- 

 ally and anatomically the same. 



86. They are of two kinds ; namely, regular or normal, and 

 adventitious or latent (119). 



87. Eegular leaf-buds are formed at the axillae of leaves. 



88. They are organs capable of propagating the individual 

 from which they originate. 



89. They are at first nourished by the fluid lying in the 

 pith, but finally establish for themselves a communication with 

 the soil by the woody matter which they send downward. 



90. Their force of development will be in proportion to their 

 nourishment ; and, consequently, when it is wished to procure 

 a young shoot of unusual vigor, all other shoots in the vicinity 

 are prevented growing, so as to accumulate for one shoot only 

 all the food that would otherwise have been consumed by 

 several. 



91. Cutting back to a few eyes is an operation in pruning to 

 produce the same effect, by directing the sap, as it ascends, into 

 two or three buds only, instead of allowing it to expend itself 

 upon all the others which are cut away. 



92. When leaf-buds grow, they develop in three directions ; 



