66 



NATURE STUDY AND LIFE 



Fig. 22. Egg Raft laid by a 

 Single Mosquito 



After the snow and ice disappear in spring, let each 

 child keep careful watch for eggs and wrigglers, in any 

 stagnant pools, water pails, tubs, or barrels standing 

 outdoors about his own home, and note the date and 



bring in specimens in a bottle 

 filled with the water in which 

 they are found. 



As soon as the wrigglers 

 appear in numbers, arrange 

 an aquarium with a single little fish, preferably a native in 

 the locality, — sunfish, perch, pickerel, pout, bass, shiner, 

 dace, — but a goldfish will do. You will not have fed the 

 fish the day before this lesson. Gather the class about 

 the aquarium, and as you pour in a tumblerful of wrigglers 

 ask each to count how many the fish takes for a meal. 



In another aquarium keep a large 

 quantity of wrigglers. Have the top 

 securely covered with gauze, so that 

 none may escape into the room, and 

 observe from time to time to see them 

 moult their skins, until a number have 

 passed through the larval stages and 

 emerged as adult mosquitoes. 

 Then, at the beginning of the 

 nature-study lesson, put a few 

 drops of kerosene oil on the water 

 and let the children observe the 

 result. Within a few minutes all the wrigglers will have 

 been killed, and as the mosquitoes touch the oily surface 

 they sink down and drown. A mosquito can walk on 

 water, as the children should already have observed in 



Fig. 23. Mosquito Pupa 

 (After Howard) 



