ARTHROPODA. 



273 



aphis. ' To what orders do they belong and what modes 

 are being used to meet their ravages? 



26. Metamorphosis among the insects. How prevalent 

 is it? What advantages has it over direct development? 



27. Why have arthropods not succeeded in producing 

 large massive bodies like the vertebrates or some mollusks ? 



28. The real underlying meaning of the statement that 

 the number of the species of kisects is greater than of all 

 the rest of the animal kingdom beside. 



29. Make special studies of the habits and activities 

 of members of this phylum during the spring months. 



30. Make a list of all the noxious insects known by you 

 to be found in your locality. In what ways do they work 

 their injury? What are the best methods of control? 

 Why? 



