50 Mosquitoes 



ing, over thirty miles away, in the pine region where 

 none breed locally. 



In the spring of 1904 the ditching of the Shrews- 

 bury River marshes minimised the surrounding ter- 

 ritory for cantator, while in the unditched Newark 

 marshes the brood developed and went to Bernards- 

 ville, where ordinarily mosquitoes are unknown. 



Dr. Smith has observed that in the salt-marsh 

 migration the females almost invariably have unde- 

 veloped ovaries. He has examined great numbers 

 of specimens from the same swarm for a period of 

 over a month, so that the eggs would have had 

 plenty of time to develop. He attributes the migra- 

 tion to a restlessness due to the inability to repro- 

 duce. This may be a desire to suck blood, since in 

 this species, as in many others, blood seems to be 

 necessary to the development of the eggs. He 

 thinks it probable that these specimens had not yet 

 bitten, those which had done so would, at least in 

 all probability, attempt to return to the marsh and 

 would not be likely to be caught. 



Dr. L. O. Howard in his admirable book, Mos- 

 quitoes, quotes a letter from the Hon. J. D. Mitch- 

 ell of Victoria, Texas, in which two most remarka- 

 ble migrations of mosquitoes are described. The 

 first migration, which occurred in October, 1879, was 

 from east to west, in a line about three miles wide, 

 about fifty feet high, coming from a marsh about 

 thirty-five miles distant, during a fairly strong east- 

 erly wind which had been blowing for about three 

 days prior to the time when the insects arrived. 

 The passage occupied about five days, enough mos- 



