100 RIPENING FRUIT. 



Although fruit 'has, in common with leaves, the property of 

 elaborating the sap, yet there is this difference between them ; 

 that, whUe leaves return back into the stem what matters they 

 form, fruit retains the principal part of what it secretes for the 

 use of itself or of the seeds it contains. This difference is 

 probably to a considerable extent dependent upon the imperfect 

 condition of the fruit-stalk, which has little power of carrying 

 off from the fruit the matter which is formed within it. In 

 those cases, however, in which the fruit has stomates, the 

 aqueous particles are given off through the surface of the fruit 

 which then becomes hard or dry when ripe ; but in others, in 

 which there are no stomates, or few, or imperfect ones, aqueous 

 particles cannot be extricated to any considerable amount, and 

 the fruit becomes succulent. 



The maturation of the fruit is dependent, then, upon the 

 action of the leaves and roots, and the secretions that it forms 

 are principally derived from the former. Consequently, 

 whatever contributes to the healthy condition of the leaves 

 and roots will have a directly beneficial influence upon the 

 fruit, and vice versa. It is, however, certain, that the juices 

 furnished by the leaves undergo a further alteration by the 

 vital forces of the fruit itself, which alteration varies according 

 to species. Thus the fruit of the Peach is sweet, but there is 

 no perceptible sweetness in its leaves ; and the fruit of the Fig 

 is bland and wholesome while the leaves of that plant are acrid 

 and deleterious. 



Among the immediate causes of the changes that occur in 

 the secretions of fruit are heat and light ; without which the 

 peculiar qualities of fruits are imperfectly formed, especially in 

 species that are natives of countries enjoying a high summer 

 temperature. It is found that among the effects of a high 

 temperatinre and an exposure to bright light is the production 

 of sugar and of certain flavours ; and that under opposite 

 circumstances, acidity prevails. 



In this respect, fruit only obeys the general laws which 

 regulate the formation of vegetable secretions. Heat and light 

 are unquestionably the agents, though perhaps not the sole 

 agents, upon which all the quahties of plants depend. For 



