AMERICAN MUSEUM GUIDE LEAFLETS 



obliged to flee from the intolerable swarms of gnats that descended upon 

 them. 



Certain artificial agents seem to play some role in the dissemination 



„. . . of mosquitoes. Railway trains are said to he responsible 

 Dissemination ... ' . . 



for the distribution of the insects, and tracts which have 



been practically free from the pest are thought to have been invaded as 



the railroad lines opened up the country. One species occurring in 



Australia is supposed to have been "imported from Europe in the 



watertanks of some old sailing vessel." 1 At the port of New York a 



I Genera/ distribution of Anopheles 



FIG 2. THE DISTRIBUTION OF ANOPHELES 



After Theobald. 



very abundant SMM Distribution of A maculipennis 



do/en foreign species have been observed on ships in quarantine. Mos- 

 quitoes are also carried by the wind. The fact that hosts of adult 

 mosquitoes are to he found in localities where not a single larva of 

 the species may he discovered, led Professor John B. Smith, of New 

 Jersey, to investigate the question of migration of mosquitoes, and he 

 has learned that large swarms of them may, with a moderate wind, fly 

 or drift thirty or forty miles. Shore mosquitoes are found far inland, 

 and, on the other hand, swarms have been seen many miles out at sea. 



'Skuse, as cited by Theobald, Culicidse of the World. Vol. 1, p 82 



