I 88 THE TEACHING BOTANIST 



(1) Why do the cotyledons remain below 



ground in this Bean, and rise above 

 it in the Lima Bean ? 



(2) What effect is produced by this differ- 



ence upon the growth of the hypo- 

 cotyls ? 



(3) Where is the terminal bud which con- 



tinues the growth of the stem ? 



1 8. After the same manner study the Morning-glory 



seedling. 

 Why does the plumule develop so late ? 



19. After the same manner study the Corn seedling. 

 From what parts do the upper roots come ? Is 



there anything similar in adult Corn plants ? 



20. From your observations deduce the morphological 



nature of hypocotyl, cotyledon, and plumule. 

 Express in a sentence. 



21. Construct a series of four generalized diagrams 



of the seedlings studied, expressing in colors 

 (identical with those used in Exercise 7) the 

 comparative morphology of the four seedlings, 

 in comparison, with one another and with the 

 seeds from which they grew. 

 (Place if possible on the same page with those 

 of Exercise 7.) 



22. You have observed in your boxes of seedlings 



the turning of the plants toward the lightest 

 side ; and this turning toward the light is very 



