TYPICAL FRUITS 231 



Method (Field)- Go into the woods, fields, and parks and 

 make a collection of as many examples as possible to illus 

 trate seed dispersal. 



Bring them together and mount, label, and classify accord 

 ing to the method of dispersal represented. 



Make drawings of each type found and supplement speci- 

 mens with pictures. 



Query. How are poppy seeds scattered ? How can 

 you account for the occurrence of poison ivy along the 

 fences bordering country roads? How are cedar trees so 

 often found along roadsides at quite regular intervals as if 

 planted by man? 



Suggestions. (1) Test various common fruits for the 

 nutrients. Sugar will naturally be found in most sweet 

 fruits. Which fruits contain protein, starch, oils? Which 

 have the greatest amount of water? 



(2) Test ripe and unripe fruits of the same sort such as 

 green apples and ripe apples. How do they differ in their 

 food content? 



197. SAP FLOW IN FRUITS 



Method. Find out where the sap flows in a fruit, 

 by making an experiment similar to experiments on sap 

 flow in roots, stems, and leaves. Cut off and place with 

 the peduncle (stem or fruit stalk) immersed in eosin or methyl 

 green dye. After a few hours, cut open the fruit and see 

 what structures have become stained with the color. Does 

 it reach the seeds? What light does this exercise throw on 

 the use of the hilum of seeds ? 



Note. Cucumbers, gourds, okras, and other garden fruits when 

 unripe will give excellent results. 



