RIPENING AND PRESERVING FRUITS. 279 



thing frequently takes place in young trees with abundance 

 of sap, and in cases where a large supply of water has 

 been given artificially." Travelers, who have eaten the 

 magnificent specimens of fruits produced by irrigation, in 

 California, tell us that they are deficient in flavor, and the 

 same thing is sometimes observed as a result of an unusu- 

 ally wet season. 



" It is not easy in all cases to determine the exact time 

 when the fruit is ripe. In dry fruits, the period immedi- 

 ately before dehiscence,* is considered as that of matura- 

 tion ; but in pulpy fruits, there is much uncertainty. It 

 is usual to say that edible fruits are ripe when their in- 

 gredients are in such a state of combination as to give the 

 most agreeable flavor.. After such are ripe, in the ordi- 

 nary sense, so as to be capable of being used for food, 

 they undergo further changes by the oxidation of their 

 tissues, even after being separated from the plant. In 

 some cases these changes improve the quality of the fruit, 

 as in the case of the medlar, the austerity of which is 

 thus still further diminished. In the pear, this process 

 renders it soft, but still fit for food, while in the apple it 

 causes a decay which acts injuriously on its qualities. By 

 this process of oxidation, the whole fruit is ultimately re- 

 duced to a putrescent mass, which probably acts bene- 

 ficially in promoting the germination of the seeds when 

 the fruit drops on the ground. 



" The periods of time required for ripening the fruit, va- 

 ries in different plants. Most fruits ripen within a year 

 from the expansion of the flower, some come to maturity 

 within a few days, others require months. Certain plants, 



* Bursting open of the pods, or of the hulls of nuts. 



