266 



TYPICAL FLOWERING PLANTS 



test for sugar. If the latter is present, the mixture will 

 become dull orange when heated. Test uncooked seed for 

 oil (1) by heating it over a lamp on a sheet of linen paper ; 

 (2) by soaking it over night in ether. (This must not be 

 near a flame at any time.) If oil is present, it will show 

 on the paper as a clear spot, and in the second test the 

 oil will appear on the surface of the ether in the test 

 tube. 



Make a record of the results as indicated below: 



205. Digestion of the Food in the Seed. — It may appear 

 strange that the growing bean plant lives upon the food 

 stored in the cotyledons, and yet such is the case. But this 

 food must undergo a real digestion before the bean embryo 

 can use it. We do not know just how this digestion takes 

 place in the bean, but in the corn, as we have learned, 

 there is a special structure, the scutellum, which helps to 

 digest the food in the endosperm. This corn scutellum 

 may be removed from the corn seed and made to digest 

 other kinds of starch, for instance, that obtained from a 

 finely grated potato. This should be kept warm and 

 moist for several hours, after which it may be tested for 

 sugar with Fehling's solution (See page 265). When 

 scientists learn more about the digestive processes of 

 plants they will probably find that they are similar to 

 the digestive processes of animals. 



