8 PLANT LIFE 



Two Kinds of Buds.— Nearly all woody plants, notably the 

 fruit trees and shrubs, form two kinds of buds — one kind for the 

 formation of flowers and fruit and another for the growth of shoots 

 next year. 



These two kinds often differ in appearance enough so that the 

 fruit grower may be able to distinguish between them in the autumn 

 and winter. This is notably true on such trees as peaches, plums, 

 and cherries. The fruit buds are usually shorter or more plump 

 and are less tapering at the point. On these trees there may be 

 one or two fruit buds formed in the same leaf-angle as a shoot bud. 

 Thus if we see two or more buds located together on the sides of 

 twigs, at least one of each group is likely to produce fruit. The 

 grower can often foretell the prospect for fruit. 



FIELD AND LABORATORY EXERCISES 



1. Oxygen from Plants. — In a glass jar of water let a large supply of algae 

 or other water plants be placed for growth. Over the plants invert a glass 

 funnel and a test tube or bottle in a manner to catch the oxygen given off by 

 the plants. Place the jar in a sunny place for a few hours and test for the pres- 

 ence of oxygen in the bottle by the use of a glowing splinter. What has been 

 taking place? 



2. Disappearance of Chlorophyll. — Place a board over some green grass so 

 as to exclude the light for a few days. Then note the change in color of the grass 

 Will crops growing in shaded places make as much growth as those in the light? 

 Name some plants that endure shade well. 



3. Effect of Available Plant Food. — Compare growth of plants of the same 

 kinds on poor soils and rich soils. What are the chief differences? From which 

 would you prefer to save seeds? 



4. Structure of Leaves. — If a strong microscope is available, mount in 

 water on a glass slip a piece of epidermis torn from a leaf. Try several kinds. 

 Study the stomates and the chlorophyll-bearing cells. Also make cross-sec- 

 tions by placing the leaf between two pieces of pith and cutting with a razor. 

 Thin sections will show under the microscope somewhat as shown in figure 1. 



5. Exercises in germination may be devised to show the best conditions 

 for seed growth. After reading the conditions in this chapter, try them by 

 germinating seeds under as many conditions as you can find to show the effects 

 of proper moisture, warmth, and air. 



6. Osmosis. — Try some experiments to show osmotic action. (1) Arrange 

 an apparatus as shown in figure 4. Have water in the large glass and a strong 

 sugar syrup in the funnel tube. The membrane tied closely over the funnel 

 mouth may be from a bladder or from a large intestine used over a piece of 

 sausage. The funnel tube may be extended to any height desired by connect- 

 ing more glass tubing through short pieces of rubber tubing. (2) An exercise 

 with egg osmosis is described in Chapter I of Productive Farming. Repeat 

 this. (3) Soak a withered potato or apple in water and explain the results. 

 Soak a fresh apple in strong syrup and explain why it shrivels. 



7. Nitrogen in Air. — Invert a glass jar full of air, with the mouth immersed 

 in a vessel of water over which is floating a large cork supporting a small burn- 

 ing candle. The candle will continue to burn for a short time in the jar of air 

 and the water will slowly rise in the jar. When the flame goes out because of 



