HABITS OF ANOPHELES i6i 



has flowed the fluid which, it is no exaggeration to 

 say, has changed the face of continents, and pro- 

 foundly affected the fate of nations. 



It is an interesting fact that, amongst the Culicidae, 

 it is the female alone that bites. The mouth-parts of 

 the male are weaker, and seem unable to pierce the 

 skin. It has been suggested that a meal of blood is 

 necessary for the development of the eggs ; but the 

 evidence for this is not conclusive. There must be 

 millions and millions of mosquitoes in sparsely in- 

 habited or uninhabited districts, in Africa, in Finland, 

 in Northern Asia, and America, which never have a 

 chance of sucking blood ; and it is impossible to 

 believe that these millions do not lay eggs. 



The female is undoubtedly greedy. If undisturbed, 

 she simply gorges herself until every joint of her 

 chitinous armour is stretched to the cracking- point. 

 At times even, like Baron Munchausen's horse after 

 his adventure with the portcullis, what she takes in 

 at one end runs out at the other. But she never 

 ceases sucking. The great majority of individuals, 

 however, can never taste blood, and subsist mainly 

 on vegetable juices. In captivity they cannot last 

 longer than five days without food and drink ; but 

 they can be kept alive for weeks on a diet of bananas, 

 pineapples, and other juicy fruits. 



Anopheles is often conveyed great distances by the 

 wind, or in railway trains or ships ; but of itself it 

 does not fly far; about five or six hundred yards — 

 some authorities place it much lower — is its limit. 

 Beyond this distance they do not voluntarily stray 

 from their breeding-places. Both Anopheles and Culex 

 lay their eggs, as is well known, in standing water, 

 and here three out of the four stages in their life- 

 history — the egg, the larva, and the pupa — are passed 

 through. The larva and the pupa hang on to the 

 surface-film of the water by means of certain sus- 



II 



