14 



NATURE STUDY. 



wrigglers were found is the best for the purpose. No special feeding 

 is necessary; the organic matter in the stagnant water suffices. Do 

 not put too many wrigglers into too small a jar of water. The 

 mouth of the jar containing pupae should be covered with cheese- 

 cloth, so as to prevent the escape of the winged mosquitoes which 

 will emerge from the pupse. With half a dozen jars of material, 

 the life history and habits of the mosquito can be admirably ob- 

 served. All of the changes of the mosquito from egg to adult are 

 completed in three or four weeks. 



Observing and Questioning- 



What is the wrig- 

 gling of the wrigglers? 

 Evidently simply the 

 peculiar mode of 

 swimming or moving 

 thru the water. It is 

 a violent lashing of 

 the tail end of the 

 body. The wrigglers 

 move in any direction 

 at will by means of 

 this lashing. If a 



IflG.:*. The Pupa, b t, breathing tube; sf, swimming flaps Wriggler whlch IS 



at the tip of the body. swimming thru the 



water stops "wriggling" i. e. stops swimming, what happens? It 

 slowly sinks. (If it touches the walls of the jar it may not sink 

 because of the friction.) Why does it sink ? And why so slowly? 

 It is evidently heavier (denser) than water, but only slightly so. 

 There are, however, always many wrigglers hanging head 

 downward just beneath the surface of the water; hanging down in 

 fact from the surtace of the water. What are they doing ? 

 Breathing. 



