124 



HISTORY OF THE GROWTH OF A TREE. 



ficient to produce twenty inches of increase. 

 Of these little stunted branches, called 

 spurs, the terminal bud acquires a swollen 

 appearance, and at length, instead of 

 giving birth to a new shoot, produces from 

 its bosom a cluster of twigs in the form of 

 pedicels, each terminated by a bud, the 

 leaves of which are modified for the pur- 

 poses of reproduction, grow firmly to each 

 other, assume peculiar forms and colours, 

 and form a flower, which had been en- 

 wrapped and protected from injury during 

 the previous winter by several layers of 

 imperfect leaves, now brought forth as 

 bracts. Sap is impelled into the calyx 

 through the pedicel by gentle degrees, is 

 taken up by it, and exposed by the surface 

 of its tube and segments to air and light ; 

 but, having very imperfect means of return- 

 ing, all that cannot be consumed by the 

 calyx is forced onwards into the circulation 

 of the petals, stamens, and pistil. The 

 petals unfold themselves of a dazzling 

 white tinged with pink, and expose the 

 stamens ; at the same time the disc chan- 

 ges into a saccharine substance, which is 

 supposed to nourish the stamens and pistil, 

 and give them energy to perform their 

 functions. 



At a fitting time, the stigmatic surface 

 of the pistil being ready to receive the pol- 

 len, the latter is cast upon it from the an- 

 thers, which have remained near for that 

 particular purpose. When the pollen touch- 

 es the stigma, the grains adhere by means 

 of its viscid surface, emitting a delicate 

 membranous tube, which pierces into the 

 stigmatic tissue, lengthens there, and con- 

 veys the matter contained in the pollen 

 towards the ovules, which the tube finally 

 enters by means of their foramina. 



This has no sooner occurred than the 

 petals and stamens fade and fall away, 

 their ephemeral but important functions 

 being accomplished. The sap which is af- 

 terwards impelled through the peduncle 

 can only be disposed of to the calyx and 

 ovary, where it lodges : these two swell 

 and form a young fruit, which continues to 

 grow as long as any new matter of growth 

 is supplied from the parent plant. At this 

 time the surface of the fruit performs the 

 functions of leaves in exposing the juice to 



light and air ; at a subsequent period it' 

 ceases to decompose carbonic acid, gains 

 oxygen, loses its green colour, assumes the 

 rich ruddy glow of maturity; and the pe- 

 duncle, no longer a passage for fluids, 

 dries up and becomes unequal to support- 

 ing the fruit, which at last falls to the 

 earth. Here, if not destroyed by animals, 

 it lies and decays : in the succeeding spring 

 its seeds are stimulated into life, strike 

 root in the mass of decayed matter which 

 surrounds them, and spring forth as new 

 plants to undergo all the vicissitudes of 

 their parent. 



Such are the progressive phenomena in 

 the vegetation, not only of the apple, but of 

 all trees which are natives of northern 

 climates, and of a large part of the herbage 

 of the same countries, modified, of course, 

 by peculiarities of structure and constitu- 

 tion ; as in annual and herbaceous plants, 

 and in those the leaves of which are oppo- 

 site and not alternate : but all the more 

 essential circumstances of their growth are 

 the same as those of the apple tree. 



If we reflect upon these phenomena, our 

 minds can scarcely fail to be deeply im- 

 pressed with admiration at the perfect sim- 

 plicity, and, at the same time, faultless skill, 

 with which all the machinery is contrived 

 upon which vegetable life depends. A few 

 forms of tissue, interwoven horizontally and 

 perpendicularly, constitute a stem ; the de- 

 velopment, by the first shoot that the seed 

 produces, of buds which grow upon the 

 same plan as the first shoot itself, and a 

 constant repetition of the same formation, 

 cause an increase in the length and breadth 

 of the plant ; an expansion of the bark into 

 a leaf, within which ramify veins proceed- 

 ing from the seat of nutritive matter in the 

 new shoot, with a provision of air-passages 

 in its substance, and of pores on its surface, 

 enables the crude fluid sent from the root 

 to be elaborated and digested until it be- 

 comes the peculiar secretion of the species ; 

 the contraction of a branch and its leaves 

 forms a flower ; the disintegration of the 

 internal tissue of a petal forms pollen ; the 

 folding inwards of a leaf is sufficient to 

 constitute a pistil ; and, finally, the gorging 

 of the pistil with fluid which it cannot part 

 with causes the production of a fruit. 



