34 INTERRELATIONS OF PLANTS AND ANIMALS 



b. Collections 



Method and Observations. — Collect as many different sorts of 

 insects as possible and bring them to your instructor, who will 

 help you name your specimens. You will study these specimens in 

 detail when you return to school, so be careful not to injure them. 



Problem 9: How to know an insect. 



Materials. — Any living or dead insect, bee, butterfly, or grass- 

 hopper preferred. Hand lens. 



Method. — Carefully examine any insect. 



Observations. — Notice that the body is divided into three 

 regions : the head; a middle part, the thorax; and a hind part, 

 the abdomen. (See Figs., pp. 29, 30, Civic Biology.) These parts 

 are further divided into joints {segments). Look at the head. 

 Find the feelers (antennae), the large compound eyes, and certain 

 movable mouth parts. What do you find attached to the thorax ? 

 How many pairs? Look carefully along the sides of the abdo- 

 men for very tiny breathing holes (spiracles) . All insects breathe 

 by a system of air tubes (trachece) opening along the sides of the 

 body. The characters you have just found should enable you to 

 distinguish an insect from all other animals. 



Conclusion. — 1 . Write a paragraph telling what structural char- 

 acters an insect has. 



2. Make a drawing of an insect to show all the parts that we 

 have seen above. Label each part. 



Problem 10: To learn to recognize insects that frequent 

 flowering plants. 



Method. — This work may best be taken on a field trip, although 

 laboratory work from boxes containing mounted insects of differ- 

 ent groups may well be substituted. 



NOTE. — Insects have been shown to be animals that have three jointed parts to 

 the body, three pairs of jointed legs, feelers, compound eyes, and a more or less hard 

 skeleton on the outside of the body. They may or may not have wings. They 

 breathe through a system of air tubes called trachece. 



The following orders or groups of insects are likely to be found 

 feeding or living upon flowering plants. The position and kind 



