SEEDLINGS 1 07 



expected that any one class will have time to complete 

 them all, but a number are suggested in order that dif- 

 ferent teachers may choose the ones best suited to their 

 circumstances. 



PRACTICAL QUESTIONS 



1. What are the principal external conditions that atFect germi- 

 nation? (137,138,139,140.) 



2. What effect has cold? Want of air? Too much water? 



3. Is light necessary to germination? 



4. What is the use of*clipping seeds ? 



5. In what cases should it be resorted to? 



6. Why will seed not germinate in hard, sun-baked land without 

 abundant tillage ? Why not on undrained or badly drained land ? 



(138, I39-) 



7. Will seeds that have lost their vitality swell when soaked? 



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

 boiled into jam have sometimes been known to germinate?^ (142.) 



9. Could such a thing happen in the case of apples or watermelons, 

 and why or why not ? (142.) 



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 ? (144.) 



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? 



SEEDLINGS 



Material. — Seedlings of various kinds in different stages of 

 growth. Tho.se from seeds experimented with in Sections 137-144 may 

 be used to begin with. Corn, oats, bean, squash, cotton, are the ones 

 mentioned in the text. Ash, maple, morning-glory, or castor bean 

 may be used instead of cotton, but the last two are rather difficult 

 to germinate, requiring from 8 to 10 days, or even longer, if the 

 temperature is too low. Soaked seeds of cotton and corn will ger- 

 minate in from 3 to 7 days, according to the temperature; oats in 

 I to 4, beans in 4 to 6, squash in 8 to 10. Germination will be 

 greatly facilitated by soaking the seeds for 12 to 24 hours before plant- 

 ing them, and very obdurate ones may be forced by clipping. 



1 Vines, " Lectures on the Physiology of Plants," p. 2S2. See also, Sachs, 

 " Physiology of Plants." 



