small runnels of water, in pools of rain water on rocks, on 

 the margin of slow running streams, and sometimes, but 

 rarely, in vessels of water. These larvae float flat on the 

 surface of the water like sticks, and move with a peculiar 

 backward skating movement. The Anopheles bite mostly 

 at night. 



(5) The larvae of all kinds of gnats require at least six 

 or seven days' life in water before they reach maturity and 

 become winged insects. They cannot withstand thorough 

 drying. Nor can the eggs. 



(6) Adult mosquitoes (that is, the winged insects) may 

 live for months even in captivity. They hibernate in cold 

 climates, and can resist severe frost or severe heat. They 

 feed on fruit and leaves, on cattle and birds, as well as on 

 men. As a rule it is only the females which feed on 

 blood. 



(7) It is now a matter of the general experience of 

 many investigators, that where mosquitoes abound in a 

 house, their larvae can usually be found at a short distance, 

 say within a few hundred yards from the house. Occa- 

 sionally, where the house is isolated, and no stagnant water 

 is in its immediate vicinity, mosquitoes may attack it from 

 a greater distance ; but this is exceptional, and in the great 

 majority of cases, especially in towns, almost every house 

 breeds its own mosquitoes in its backyards, or in puddles 

 and drains in the streets close by. 



(8) Mosquitoes, especially Anopheles, love thick under- 

 growth. 



Further details will be found in the literature already 

 mentioned ; but most medical men at least will by this 

 time be quite familiar with such facts. 



