FLOWER-GARDENING. 147 



vided against injury to plants by excessive fecundity, in giving 

 them a power of throwing off flowers, the fruit of which cannot 

 be supported. 



229. The flavor of fruit depends upon the existence of cer- 

 tain secretions, especially of acid and sugar ; flavor will, conse- 

 quently, be regulated by the circumstances under which 

 fruit is ripened. 



230. The ripening of fruit is the conversion of acid and other 

 substances into sugar. 



231. As the latter substance cannot be obtained at all in the 

 dark, is less abundant in fruit ripened in diffused light, and 

 most abundant in fruit exposed to the direct rays of the sun, the 

 conversion of matter into sugar occurs under the same circum- 

 stances as the decomposition of carbonic acid (141 and 279). 



232 Therefore, if fruit be produced in situations much 

 exposed to the sun, its sweetness will be augmented. 



233. And in proportion as it is deprived of the sun's direct 

 rays, that quality will diminish. 



234. So that a fruit which, when exposed to the sun, is sweet, 

 when grown where no direct light will reach it will be acid, as 

 Pears, Cherries, etc. 



235. Hence acidity may be corrected by exposure to light, 

 and excessive sweetness or insipidity by removal from light. 



236. It is the property of succulent fruits which are acid 

 when wild, to acquire sweetness when cultivated, losing part of 

 their acid. 



237. This probably arises from the augmentation of the 

 cellular tissue, which possibly has a greater power than woody 

 or vascular tissue of assisting in the formation of sugar. 



238. As a certain quantity of acid is essential to render 

 fruit agreeable to the palate, and as it is the property of culti- 

 vated fruits to add to their saccharine matter, but not to form 

 more acid than when wild, it follows that, in selecting wild fruits 

 for domestication, those which are acid should be preferred, 

 and those which are sweet or insipid rejected. 



239. Unless recourse is had to hybridism, when a wild 



