RIPENING OF FRUITS. 849 
called pectose. Frémy has also noticed, that at the period of 
ripening the thickness of the cell-walls diminishes rapidly ; 
hence it would appear that these transformations of the pectic 
compounds play an important part in the changes which are 
' taking place during the ripening of the fruit. 
The changes which take place in the composition of fruits 
during ripening are well exhibited in the following table founded 
upon Bérard’s observations :— 
Water. Sugar. ones 
Names of Fruits. L | 
Unripe.| Ripe. | Unripe. Ripe. | Unripe. | Ripe. 
| 2 | 
| A trace | 
| when 
| young, 
and then 
Apricots ‘ e 2 Il BREE) 74°87 6°64 16°48 3°61 1°86 
| | With the 
seeds ; — 
Red Currants > . | 86°41 81°10 0°52 6°24 8°45 8:01 
Duke Cherries. . | 98°28 74°85 Let 18°12 2°44 I-12 
Greengage Plums . | 74°87 71°10 U7 24°81 1:26 rill 
Melting Peaches . . | 90°31 80°24 0°63 11°61 3-01 1:21 
Jargonelle Pears . . | 86°28 83°88 6°45 11°52 3°80 2°19 
z 
| 
Ripening of Fruits.—The time when a fruit is considered ripe 
varies in different cases. When the pericarp is of a dry nature, 
the fruit is looked upon as ripe just before it dehisces ; but when 
the pericarp is of a pulpy nature and edible, we commonly re- 
gard it as mature when most agreeable for food. Hence the Apple 
is considered to be ripe in astate in which the Medlar would be 
regarded as unripe. 
When succulent fruits are ripe, they undergo another change, 
a species of oxidation, which produces a decay, or bletting of 
their tissues, as it has been called by Lindley. This bletting, 
according to Bérard, is especially evident in the fruits of the 
Pomez and Ebenaceze, and it would appear that the more 
austere the fruit is, the more it is capable of bletting regularly. 
Bletting appears to be peculiar to such fruits, and may be re- 
garded as a state intermediate between maturity and decay. A 
Jargonelle Pear, in passing from ripeness to bletting, according 
to Bérard, léses a great deal of water (83°88, which it contains 
when ripe, being reduced to 62°73) ; much sugar (11°52, being 
reduced to 8°77); and a little lignin (2°19, being reduced to 
1°85) ; but it acquires, at the same time, rather more malic acid, 
gum, and albuminous matters. 
The time required by different plants for ripening their fruits 
varies much, but almost all fruits come to maturity in a few 
months. Some, as those of Grasses generally, take but a few 
31 
