68 The Living Things of the Earth unit 



31. What are the striking characteristics of sponges? 



32. What name is given to the simplest animals? How do they differ from 

 all other animals? Mention the various places where protozoa may 

 live. 



33. Give directions for making a hay infusion. What use can you make 

 of it? 



34. Define the word microorganism. Explain how the paramecium moves 

 about and eats. 



35. Describe the ameba and its habits. 



36. Of what importance are the shell-building protozoa? 



37. Imagine yourself starting on a long journey to review the animal 

 kingdom, passing your own group — the mammals — first and ending 

 with the simplest forms. Name in order the various groups you would 

 see. 



Exercises 



I. If possible obtain a large lubber grasshopper for study. Compare 

 the three body regions as to size. To which region are the legs and wings 

 (appendages) attached? How many rings or segments in the abdomen? 

 Of how m.any pieces is each segment composed? With a hand lens find 

 breathing pores or spiracles. They are connected with tubes branching 

 through the body (tracheae). How might overlapping segments help 

 the insect take in air? Describe the position of the compound eyes. Of 

 what advantage is this? Look for simple eyes. Describe. What is the ad- 

 vantage of having antennae segmented? Find a smooth oval spot, the 



Fig. 94 Month parts of 

 the grasshopper. The 

 two strong, jagged jaws 

 (A) viove fro?/! side to 

 side. They are covered 

 by the lips (B). The 

 jointed structures like 

 short feelers hold and 

 direct the food. These 

 mouth parts are well 

 protected by being 

 tough and horny. 

 (adapted from turtox 

 drawing) 



