XXIX. WATER STRIDER 



Material. — Some water striders in a large dish of water, covered 

 with a pane of glass, to prevent them from flying away. Catch tnem 

 with a net made by sewing a bag of cheese cloth to a stout wire bent into 

 a circle, and fastened to a pole. At the end of the lesson return them 

 to their home. 



Pins and sewing needles will also be needed. 



Observation. — How large is a water strider ? What 

 is its shape ? What is its color ? Has it wings ? 

 What is the shape of its mouth parts ? How many 

 legs has a water strider ? What is their shape ? 



What is the shape of the part of a water strider's 

 leg that touches the water ? Does the insect get its 

 feet wet while it is walking on the water? How 

 does the surface of the water look where a leg rests 

 upon it ? How much does a water strider disturb 

 the water when it moves? 



Carefully drop a small needle on the surface of a 

 cup of water. Can you make the needle float ? Try 

 a pin also. How does the surface of the water next 

 to the needle look ? Does the water wet the needle ? 

 See if you can make a wet needle float. Does the 

 water strider float as the needle does ? 



Drawing. — Draw a picture of a water strider as it 

 looks when it is walking on the water. 



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