10 



10. Place two small potted plants, one on each pan of a balance^ 

 Place a bell-jar over one of the plants. Counterpoise. Observe results. 



11. After a few hours take off bell-jar, wipe the moisture carefully 

 from inside and replace. Is balance restored? Explain. 



12. Tear off a small strip of epidermis from the lower surface of a 

 leaf, place in a glass side, and examine with a microscope. Note the 

 breathing- pores, their shape and number. 



13. Boil for a few minutes in water some green leaves ; remove and 

 immerse in alcohol until bleached. Notice color of solution. Place 

 bleached leaves in tincture of iodine solution. What happens and what 

 does it indicate? Try variegated leaves. 



14. Test in the same way some leaves which have been kept in 

 the dark for a few days. 



15. Place some water-cress or other water plant in a jar of water 

 and put in a sunny position. Contrive some way of collecting the gas 

 and test it. 



16. Place some soaked peas in a tall jar. Cover tightly with a piece 

 of glass. Test the gas in the jar after 24 hours with a burning match. 

 What is it? 



17. Cover a potted plant with a bell-jar. Within place a beaker 

 of clear lime-water and leave the whole in a dark room for a few days. 



18. Place a potted plant or some seedlings near a window and leave 

 for a few days without disturbing, 



19. Observe the attitude of young sunflowers during a bright day. 



(Consult Atkinson's First Studies of Plant Life). 



XII. The Conifers. 



1. What Conifers have their dry, thin bud-scales about the base of 

 the leaves? 



2. What Conifers have their needles single, but arranged on all' 

 sides of the stem? Arranged in two rows on the stem? 



3. What Conifer has single, flattened leaves, inclined to turn up- 

 ward so that the under side of the stem is nearly bare? 



4. Determine how the cones of the different species stand ; their 

 size ; their time of maturing ; and when they cast their seeds. 



5. Make short descriptions of the Conifers on the College Campus 

 with regard to (1) their leaves; (2) their cones; (3) their bark; (4) their 

 habit of branching, 



6. Determine the position of the fertile and sterile flower clusters on- 

 the stems of (1) Larch ; (2) Juniper ; (3) Yew ; (4) Arbor Vitae ; (5) Pitch 



Pine; (6) White Pine; (7) Scotch Pine; (8) Austrian Pine; (9) Norway 

 Spruce. 



