36 FUNCTIONS OF PLANTS. 



the fruit, the latter will be diminutive iu size, and imperfectly ripened, or may 

 drop off before attaining maturity. Hence the inferiority of fruits which 

 grow on naked branches, or even on branches where there is not a leaf close 

 to the fruit ; as in the case of a bunch of grapes, where the leaf immediately 

 above it has been cut off, or in that of a gooseberry, where the leaf imme- 

 diately above it has been eaten by a caterpillar. Hence it is evident that 

 the secretions formed by the fruit are principally derived from the matter 

 elaborated in the leaf or leaves next to it, and as the sap of all the leaves is 

 more or less abundant, according to the supply received from the roots, the 

 excellence of fruits depends ultimately on the condition of the roots, and the 

 condition, position, and exposition of the leaves. As a proof that the fruit 

 has a specific influence on the matter it contains, independently of the influ- 

 ence of the leaves, we have only to taste the leaf of an apple or a peach, 

 and compare it with the taste of the fruit. The sweetness of fruits under 

 ordinary circumstances is increased by warmth and light, and acidity is 

 increased by the opposite qualities. An abundant supply of water to plants 

 ripening their fruits, diminishes the intensity both of sweetness and acidity, 

 as well as of all other secretions ; and hence the advantage of withdrawing 

 water from plants in forcing -houses, or from fruit-bearing plants generally, 

 at the ripening season. 



132. The grand object of nature in producing fruit is to nourish the seed, 

 and there appears to be no other intention with most fruits in a wild state ; 

 but the art of man has, by enlarging and improving fruits by culture, ren- 

 dered them in a superior degree suitable for his nourishment, without in 

 general rendering them less fit for the nourishment of the seed. As, how- 

 ever, in a wild state, the seeds of pulpy fruits must necessarily germinate in 

 the decayed mass of pulp after the fruit is dropped and rotted on the surface 

 of the ground, so in a state of high culture it has been recommended to 

 bury the whole of the fruit, as of a peach for example, with the seed, when 

 a young plant is intended to be produced. (Beaton.) As the fruit attracts 

 its food from the stem through the fruit-stalk, so the seed attracts its nourish- 

 ment from the interior part of the fruit ; and hence in all covered seeds, or 

 what are commonly called fruits, the seed never can be separated from its 

 envelope, without being destroyed, till it is perfectly ripe. Seeds in a 

 young state are found to be of a mucilaginous consistency, like gum ; but 

 as they ripen, more carbon is deposited, and the gummy mucilaginous sub- 

 stance assumes the condition of flour or starch, which ultimately becomes 

 nearly as hard as wood. This is a wise provision of nature for the preser- 

 vation of the seed. In the immature or mucilaginous state of the seed, heat 

 and moisture easily decompose it, and consequently unripe seeds do not keep 

 well ; though when seeds are sown, it is necessary, before they germinate, 

 that their solid part should be again decomposed and made soluble. Hence 

 well -ripened seeds are so much more easily preserved than those which are 

 imperfectly ripened ; and hence also the reason why unripe seeds, provided 

 only their embryo be perfected, will germinate more quickly than ripe seeds; 

 the starch of the ripe seed having to be again reduced to mucilage, before it 

 can become soluble food. (Lymburn.} All seeds, when ripe, are dry and firm, 

 and they retain their vitality a greater or lesser length of time according to 

 their natures. In general oily seeds are the most perishable, and starchy seeds 

 the most tenacious of life. There are, however, exceptions in the case of 

 oily seeds, as in the common Cabbage, the seeds of which will retain their 



