83 
Artificial Distribution of Mosquitoes. 
to some old sailing vessels. As the railway lines extend, so this 
mosquito reaches portions of the country often hitherto exempt 
from it, and it has been, and is being, communicated to other 
places along the coasts by water traffic.” 
Professor Howard * says : “ There is a constant carriage 
inland from the marshy seacoast of very many mosquitoes.” But 
by this he does not intend to convey the idea that they are 
carried by wind or that they fly to any great distance inland. 
There are other means of conveyance, and of these railway trains 
seem to be very important. “ Many of the cars, as the writer 
knows from experience,” says Professor Howard, “ contain 
mosquitoes by hundreds. In this way unlimited quantities of 
mosquitoes are carried unlimited distances, and on emerging 
from the cars will start to breed even where mosquitoes are 
ordinarily rare, or would be rare under ordinary conditions. In 
this way even mountain resorts will get their supply of lowland 
mosquitoes. The writer knows of one instance in the Catskill 
Mountains, in New York, where the infection of a previously 
uninfected place could have been brought about in no other 
way.” 
These two modes of dispersal will explain to a very large 
extent the world-wide distribution of some mosquitoes, first 
their passage by water and their spread further and further 
inland by train. 
But I cannot see how they can account for European species, 
such as G. mimeticus and G. annulatus, occurring in the North- 
West Provinces of India, and not, as far as we know, in any 
intervening places between there and their native home. 
Were they to be found elsewhere between their single inland 
locality and the sea coast, or even abundant in some port, we 
could more readily imagine that they had been transported by 
such agencies , but as transport by rail can date back to no very 
great age it seems strange that in so short a space the land 
colony either at some port or neighbouring place and the 
intermediate ones should have died out, and it is impossible to 
believe that pregnant G. mimeticus or G. annulatus could have 
taken a sea voyage of some thousands of miles and then a long 
journey by train to the North-West Provinces, and established 
their species on a firm basis thousands of miles from their 
original home, Europe. We may of course still find these and 
other European species between the Himalayas and the coast, 
* Bull. No. 25, “ Mosquitoes of United States,” p. 14. 
g 2 
