240 



A YEAR IN SCIENCE 



Cockleburr Beggar's-tick 



Fig. 105. Some fruits which are 

 carried by animals. 



ticks have hooks, or spines, which 

 enable them to cling to the hair, fur, 

 or feathers of animals. They may be 

 carried many miles before they are 

 brushed off. Sometimes seeds or 

 fruits may fall into water. Such seeds are buoyant and 

 are frequently carried many miles before they are 

 deposited. 



Fig. 104. Fruits of 

 dandelion. 



Questions 



1. By what .methods may new plants arise from 

 old ones? Give examples of plants illustrating each 

 of these -methods. 



2. What is the function of a flower? 



3. Describe the structure of a typical flower. 



4. Which parts of a flower are necessary to form 

 a seed? 



5. What is an egg cell? A sperm cell? 



6. Define fertilization. 



7. How is a seed formed? 



8. Define pollination. 



9. Discuss the tw r o kinds of pollination. 



10. What are the principal agencies by means of 

 which cross pollination is accomplished ? 



11. Name flowers which are wind pollinated. 



