204 FLOWERraG AND ITS CONSEQUENCES. 



CHAPTER VII. 



OP FLOWERING AND ITS CONSEQUENCES. 



366. Plants have thus far been considered only as respects 

 their Organs of Vegetation, — those which essentially constitute 

 the vegetable being, by which it grows, deriving its sujiport from 

 the surrounding air and soil, and converting these inorganic mate- 

 rials into its own organized substance. As every additional supply 

 of nourishment furnishes materials for the development of new 

 branches, roots, and leaves, thus multiplying both those organs which 

 receive food and those which assimilate it, it would seem that, apart 

 from accidents, the increase and extension of plants would be limited 

 only by the failure of an adequate supply of nourishment. After a 

 certain period, however, varying in different species, but nearly con- 

 stant in each, a change ensues, which controls this otherwise indefi- 

 nite extent of the branches. A portion of the buds, instead of elon- 

 gating into branches, are developed in the form of Flowers ; and 

 nourislmient which would otherwise contribute to the general in- 

 crease of the plant, is devoted to their production, and to the matu- 

 ration of the fruit and seeds. 



367. Flowering an Exhaustive Process. Plants begin to bear flowers 



at a nearly detei'minate period for each species ; which is dependent 

 partly upon constitutional causes, and partly upon the requisite sup- 

 ply of nutritive matter in their system. For, since the flower and 

 fruit draw largely upon the powers and nourishment of the plant, 

 Avhile they yield nothing in retui-n, fructification is an exhaustive 

 process, and a due accumulation of food is requisite to sustain it.* 



* When the branch of a frait-tree, which is sterile or does not perfect its blos- 

 soms, is ringed or (jirdled (by the removal of a narrow ring of bark), the elab- 

 orated juices, being arrested in tlieir downward course, are accumulated in the 

 branch, which is thus enabled to produce fruit abundantly ; while the shoots that 

 appear below the ring, being fed by the much weaker ascending sap, do not 

 blossom, but push forth into leafy branches. So the flowers of most trees and 

 sln-ubs tliat bear large or fleshy fruit are produced from lateral buds, resting 

 directly upon the wood of the previous year, in which a quantity of nutritive 

 matter is deposited. So, also, a seedling shoot, which would not flower for 

 several years if left to itself, blossoms the next season when inserted as a graft 

 into an older trunk, from whose accumulated stock it draws. 



