How Far Mosquitoes Fly 51 



quitoes remaining on the ground " to make every- 

 thing uncomfortable for about two weeks." The 

 second migration occurred in October, 1886, this 

 swarm not crossing Carancahua Bay on the east, as 

 did the other, but confining itself to the Matagorda 

 Bay shore line on the west, reaching about half a 

 mile inland, but in no less numbers than in the 

 former and wider line. This time there was a light 

 wind from the south that did not hinder the western 

 flight of the swarm, which proceeded at a height of 

 about twelve feet. The enormous numbers may be 

 imagined from Mr. Mitchell's description : " They 

 clouded the sky, bent down the grass with their 

 weight, and made all driftwood and ground the 

 same color." The swarm took about three days to 

 pass and the total distance traversed was between 

 fifty and sixty miles. 



Although swarms have been reported as far as 

 fifteen miles out at sea, these flights are not normal, 

 the chilly air at the water-line usually inducing the 

 insects to settle; also the normal flight is always in- 

 land when there is either no wind or a favourable one, 

 seaward flights being only forced upon the insects 

 by a high temperature and a stiff land breeze. 1 



The subject of migration and flight should not be 

 closed without reference to the spreading of mos- 

 quitoes by cars, steamers, and other artificial means. 

 Until Dr. Howard directed public attention to the 

 dissemination of the pests in this manner, such 

 methods of dispersal had probably been overlooked, 

 although a matter of common observation to every 



1 Smith, 



