FUNCTION.] GENERAL CONSIDERATIONS. 



peduncle, no longer a passage for fluids, dries up and becomes 

 unequal to supporting 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 constitution ; as in annual and herbaceous 

 plants, and in those the leaves of which are opposite 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 impressed with admiration at the perfect 

 simplicity 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 perpen- 

 dicularly, constitute a stem; the development, 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 proceeding from the seat of nutri- 

 tive 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 

 becomes 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. 



In hot latitudes there exists another race of trees, of which 

 Palms are the representatives ; and in the north there are 



