SUMMARY 87 



Which do you think would specialize and change their 

 parts more rapidly, the bee or the grasshopper ? Why ? 



Would all species of the same genus change with the 

 same rapidity? Would the same 'species all be alike? This 

 produces what we call varieties in certain species. 



For example, all dogs belong to the same species, but 

 there is quite a difference between the Newfoundland and 

 the Poodle. The different varieties of dogs have been pro- 

 duced by taking advantage of the natural differences of 

 dogs and subjecting the animals to different surroundings 

 which have developed different physical and mental traits. 



In the same way insects of a certain species being already 

 somewhat different, when subjected to varying conditions 

 become different enough to be placed in different varieties 

 and sometimes in different species. 

 . Make lists in answer to the following questions : 



(i) What insects use the mouth parts for biting? 



(2) What insects use the mouth parts for sucking? 



(3) What insects use their legs fo'r crawling or walk- 

 ing? 



(4) What insects use their legs for alighting only? 



(5) What insects use their front wings for balancers 

 only? 



(6) What insects use their hind wings for balancers? 



(7) What insects fly with both pairs of wings? 



(8) What insects fly with one pair of wings? 



(9) What insects have no wings? 



(10) What insects in the mature state eat animal food? 



(11) What insects in the larval state eat animal food? 



(12) What insects in the mature state eat plant food? 



(13) What insects in the larval state eat plant food? 



