THE ORGANIZATION OF THE PLANT 93 



an abundance of root hairs will be produced by the germinating seeds. 

 Examine with the microscope. 



6. Make longitudinal and cross sections of parsnip or carrot to see 

 the regions of the root. Find, draw, and label the parts. 



7. Make thin cross sections of any young root and examine with 

 the microscope for the cellular structure. 



8. Perform the experiment with osmosis described on page 63. 



9. Peel one end of a potato, set the peeled end in a dish of water, 

 make a hole an inch or more deep in the other end, and in this hole put 

 some dry sugar. Explain the moisture that appears in the hole. 



10. Cut slices of potato a quarter of an inch thick and place some 

 in salt water and some in fresh water. Account for the difference in 

 rigidity in the two sets at the end of an hour. 



11. Make cross sections of cornstalk or asparagus and compare with 

 similar sections of geranium, begonia, or any of our forest trees. Make 

 sketches to show the differences noted. 



12. In a thin section of begonia or geranium stem locate the pith, 

 wood, ducts, bast, and cortex. 



13. Get a thrifty young willow twig and girdle it by removing a 

 ring of bark an inch wide two or three inches from the lower end. 

 Stand this in water so that the girdled portion is covered. Where do 

 roots appear? What light does this throw on the passage of foods 

 and food materials through the stem ? 



14. On twigs of lilac, cherry, peach, golden bell, cottonwood, or 

 horse-chestnut locate the flower and leaf buds. 



15. Locate accessory buds in walnut, pipevine, red maple, box elder, 

 butternut, and peach. 



16. Select leaves to illustrate parallel, palmate, and pinnate vena- 

 tion. Make sketches to show the different forms. 



17. With the microscope examine the epidermis from the underside 

 of a leaf for the stomata. Draw. 



18. In a thin cross section of a leaf locate the tissues described on 

 page 72. 



19. Thrust the petiole of a geranium leaf through a small hole in a 

 piece of cardboard and place the latter so that the petiole of the leaf 

 will dip into a glass of water. Over the blade of the leaf invert a drink- 

 ing glass, which should rest upon the cardboard. Explain the presence 

 of the moisture that forms on the upper glass in a short time. 



