316 EXPERIMENTS WITH PLANTS 



The color of the fruit also undergoes changes in 

 ripening; in this, light plays a great part. Try the 

 experiment of covering a green apple (which is well 

 exposed to light) with tin -foil (held in place by elastic 

 bands), in which a circle or letter has been cut (in 

 France there is a practice of attaching photographs to 

 the fruit in this manner). 



The changes which occur in the ripening fruit, 

 whereby some substances disappear and others take 

 their places (or result from their transformation), go 

 on after the fruit is detached from the plant, as is 

 evident from the familiar practice of placing pears in 

 drawers to ripen. In order to control these processes 

 and preserve the fruit properly, special methods have 

 been developed. Thus it is found that pears which 

 ripen fully on the tree are much more gritty than those 

 gathered earlier and placed (not more than three or 

 four deep) in trays, and kept in a cool, rather dry 

 room, with little circulation of air. It is very important, 

 in picking all kinds of stalked fruits, to leave the stalk 

 attached to them, .since its removal leaves a wound, 

 which readily softens and decays. It is important to 

 keep the fruit in a cool place, arid to avoid exposing it 

 to the sun; otherwise the ripening and subsequent 

 decay will proceed rapidly. The ideal method is to put 

 the fruit in cold storage. 



Water, as well as food, is needed by fruits. Many 

 fruits when ripe contain from 90 to 96 per cent water. 



