40 PRACTICAL COURSE IN BOTANY 



abundant tillage ? Why not on undrained or badly drained land ? (Exps. 

 26, 27.) 



7. Will seeds that have lost their vitality swell when soaked? (Exp. 16. ) 



8. Are there any grounds for the statement that the seeds of plums 

 boiled into jam have sometimes been known to germinate ? ^ (."53; Kxp. 30.) 



9. Could such a thing happen in the case of apple or sunflower seed, 

 and why or why not ? (33.) 



10. Does it make any difference in the health and vigor of a plant 

 whether it is grown from a large and well-developed seed or from a weak 

 and puny one? (Exp. 33.) 



11. Would a farmer be wise who should market all his best grain and 

 keep only the inferior for seed ? 



12. What would be the result of repeated plantings from the worst 

 seed? 



13. Of constantly replanting the best and most vigorous ? 



14. Suppose seed would germinate without moisture; would this be 

 an advantage, or a disadvantage to agriculturists ? 



15. Why is a cool, dry place best for keeping seeds ? (Exps. 26, 29.) 



16. Why are the earliest tomatoes found in the market usually smaller 

 than those off ered later ? (35.) 



17. Why is continued rain so Injurious to wheat, oats, and other grains 

 before they are mature enough to be harvested? (35; Exp. 32.) 



18. Would the same effect be likely to occur in the case of very oily 

 seeds, such as flax and castor beans ? Why ? (Suggestion : try the effect 

 of putting water on a piece of oiled paper.) 



19. Explain why many seeds cannot germinate successfully without 

 air. (30, 31; Exp. 25.) 



20. Mention some of the practical advantages that a farmer, a gardener, 

 or a careful housewife might gain from experiments like those made in this 

 section. 



21. Explain why seeds can endure so much greater extremes of tempera- 

 ture than growing plants. (23, 33.) 



m. DEVELOPMENT OF THE SEEDLING 



Material. — Seedlings of various kinds in different stages of growth. 

 It is recommended that the same species be used that were studied in 

 Section III, Chapter I, or such equivalents as may have been substituted 

 for them. Enough should be provided to give each pupil three or four 

 specimens in different stages of development. Seeds, even of the same kind, 



1 Vines, " Lectures on the Physiology of Plant?," p. 282. See also Sachs, 

 *' Physiology of Plants." 



