MALES AND FEMALES 33 



The larval stages (the larval metamorphosis in- 

 cludes the pupa stage) last for twelve days in hot 

 weather. If the water is cold the metamorphosis 

 may be much delayed it may continue for a month 

 or more. But eventually the imago appears. When 

 the flying mosquito has emerged from the pupa it 

 flies slowly to the pool-side, or perhaps rests upon 

 some floating object on the way. It is very feeble at 

 first and likes to rest and feed on any food it can find. 

 It thrusts its proboscis into the water or into any 

 sodden floating matter. Then mating takes place. 



All the larvae that have developed from one egg- 

 raft do not reach maturity at the same time. Some 

 have had more food than others. Out of the three 

 hundred larvae that result from the egg-raft a very 

 large proportion become male mosquitos. If a hun- 

 dred Culex larvae are collected, and all of them 

 allowed to hatch into grown mosquitos and then 

 killed with chloroform or tobacco-smoke and exam- 

 ined, it will be found that the proportion of males to 

 females is about seven to one the males of the 

 domestic species are always the most numerous. But 

 if a mosquito net in a bedroom of a house which is 

 infested with mosquitos is examined in the early 

 morning, it will be noted that there are only one or 

 two males and perhaps twenty or thirty females rest- 

 ing on the curtain. It is easy to distinguish them. 

 In the domestic species, the males have plumed heads 

 their antennae are bushy and their palps are long. 

 If so many males are hatched from the eggs, how is 

 it that they disappear so rapidly, or are not found in 

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