172 INTRODUCTION TO BOTANY 



PROBLEMS 



1. Show how widely the botanist's use of the term fruit differs from 

 that of people who are not botanists. Make out a list of some common 

 articles of food that are properly classed as fruits though not sold under 

 that name. 



2. Show that many young seedlings live on the same kind of vege- 

 table food that human beings eat. Is this true of a very young date 

 palm? 



3. How would you perform a series of experiments to discover the 

 optimum temperature for germination of the seeds of agricultural 

 plants? What precautions would you need to take? 



4. If the prices of very low-grade red-clover seed and of high-grade 

 seed are respectively $5.20 and $15.00 per bushel, but only 18 per cent 

 of the poor seed germinates, while 96 per cent of the good seed germi- 

 nates, which is more expensive to use ? If the poorer seed contained 

 26 per cent of weed seeds and the better quality was practically pure, 

 how would this affect the question as to which kind is more economi- 

 cal ? Get some clover seed and test it to see what percentage of it will 

 grow. 



5. State some reasons why better results are obtained by sowing 

 large, plump seeds of any kind of grain or other annual plant than by 

 using small, shrunken seeds. 



6. A pound of red-clover seed contains about 300,000 seeds. Fre- 

 quently 15 pounds to the acre (43,560 sq. ft.) are sown. How many 

 plants to the square foot might such a sowing produce? Does this 

 number seem too large or too small properly to cover the ground? Is 

 it, then, a waste of seed to sow 15 pounds per acre ? Explain. 



7. How long would most useful plants of the farm and garden main- 

 tain themselves if left to grow unaided among their wild competitors ? 

 What instances of this have you ever seen ? 



8. What are some of the plants which first spring up where a piece 

 of woodland has been cleared and the clearing burned over? Explain 

 why these plants are among the first to establish themselves in such 

 places. 



9. Why are uncommon kinds of plants often found near wool- 

 cleansing establishments ? 



