XIX. THE INSECTS 



Problem XXX. A study of some animal likenesses and dif- 

 ferences, and the classification of insects (optional) . (Laboratory 

 Manual, Prob. TT^T.) 



(a) Grasshopper a straight-winded insect. 



(b) Butterfly or moth a scale-winged insect. 



(c) The typhoid fly a two-winged insect. 



(d) A beetle a sheath-winged insect. 



(e) A bug a half-winged insect. 



(/) The dragon fly a nerve-winged insect. 

 (g} The bee a membrane-winged insect, 

 (h) Summary of differences between orders. 

 (i) Making a logical definition. 



Insects the Winners in Life's Race. We are all familiar with 

 common examples of insect life. Bees and butterflies we have 

 already studied in connection with their work in the cross-pollina- 

 tion of flowers. Mosquitoes and flies all too often come to our 

 notice as pests ; the common household insects sometimes annoy 

 us, while we often hear and see in a small way the harm done by 

 insects in the field and garden. Insects are a successful group. 

 They outnumber all the other species of animals on the face of the 

 earth. They hold their own in the air, in the water, and on land. 

 Fitted in many ways to lead the successful life, they have become 

 winners in life's race. 



We have already, from our study of a bee, formed some idea of 

 what an insect is. But it would be unfair to expect to know all 

 insects from our slight knowledge of one form. Our object in the 

 study of this chapter will be to get some first-hand knowledge 

 of some common insects so that we may classify them and 

 distinguish one from another. This great group, containing more 

 than half of the known representatives of animal life on the earth, 

 is made up of a number of groups called orders. The insects 

 contained in these orders have certain characters of structure and 



