538 Introduction to the Study of Science 



Glass jars, of pint or quart capacity, make good containers. Equip 

 one with a pasteboard box having two sides covered with screen ; 

 cover the other jars with netting or wire screen. Label the jars as 

 No. 1, No. 2, and so on. Large labels on which important data may 

 be recorded are serviceable. 



In jar No. 1, containing about a pint of water obtained with the 

 wigglers, put a dozen of the larvss and a small bit of an egg-raft. 



In No. 2, with the same amount of water, put some larvae and a bit 

 of an egg-raft. Keep this jar in a dark place as cool as possible. 



In No. 3 put about one half pint of distilled water and some larvae. 



Jar No. 4 is to be half filled with pond water and supplied with 

 eggs and some larvae. Place this where the temperature may be 85 

 F. to 90 F., as upon a steam radiator or a warm water bath. 



Keep complete and exact records of your observations, arranged 

 under separate headings for each culture. Follow progress of develop- 

 ment as fully as possible. Note behavior of larvae in the different 

 media and at different temperatures and explain. Observe the larvae 

 in the distilled water. What is the source of their food? What do 

 the facts show as to the life habits of the mosquito in the larval stage ? 



Follow closely the specimens in jar No. 1, their behavior as larvae, 

 as pupae, and their transformation into the adult mosquitoes. 



Feed adult mosquitoes small pieces of banana or other juicy fruit. 

 Make outline sketches showing chief features of larvae, pupae, and adult 

 mosquito; outline sketches are even more valuable for the purpose 

 than finished drawings. When adult mosquitoes appear in No. 4, 

 transfer them to screen box on No. 1. How do the adults behave 

 toward the pupae or the latest born mosquitoes? 



Into a jar containing clear water put some larvae. As soon as 

 they have grown familiar with their habitat, and breathe as larvae do, 

 cover the surface of the water with a small amount of kerosene or coal 

 oil. How do the larvae behave? Explain the result. Other points 

 may be taken up in connection with the study in the text, and tested 

 experimentally with the captive mosquitoes. 



266. Larva. In warm weather, as in summer, the eggs 

 hatch in from sixteen to forty-eight hours. In colder weather 

 they are slower and may be weeks in hatching. Each egg 

 produces a mosquito larva, commonly known as a " wiggler." 

 While all mosquitoes in the early stages are aquatic, they 

 are also direct air-breathers. They are equipped for getting 

 oxygen directly from the air, and quickly perish when prevented 



