June, '14] BRIXTON: CULEX PIPIENS OUTBREAK 259 



river were treated. The winding course of the stream, with its brush- 

 grown banks and its rough and irregular bed, partially filled with 

 vegetation and rubbish, made the work difficult and expensive. The 

 entire cost of this work amounted to $125.31. Apparently these 

 mosquitoes were a nuisance nearly a mile distant from West River. 



Another interesting outbreak of rain-barrel mosquitoes which oc- 

 curred in 1913 in Greenwich, Conn., was described to me in a letter by 

 Mr. Edwin M. Skinner, president of the United States Drainage & Irri- 

 gation Co., of New York City. Just north of the village of Mianus, 

 there is a dam six or eight feet above tide level, formerly used 

 for furnishing power for the Palmer Brothers' gas engine plant, but 

 now abandoned for another site where steam is used. About 500 yards 

 north of the Palmer dam, is another dam about six feet high, where a 

 gristmill used to stand but of which only the sluiceway and part of the 

 water wheel remain. These dams are not used, but on account of 

 sewage emptying into the river above and between them, they are 

 allowed to remain rather than permit the sewage to be exposed. 



A short distance above the second dam there is a mill where lap- 

 robes and cheap plush goods are made from cow-hair and low grade 

 wool. A cheap grade of oil is used in spinning the raw wool and cow- 

 hair, and the product is washed with water from the river which again 

 flows into the stream. Probably dye stuffs are also used and emptied 

 into the river. These waste materials, together with the sewage held 

 back by the dams, probably destroyed the fish and furnished an ideal 

 breeding-place for rain-barrel mosquitoes. The stream flow was 

 slight in the period of drought, and the water was stagnant and slimy 

 and thick with wrigglers. The river is about 100 feet wide by the 

 gristmill dam and perhaps 150 feet broad at the Palmer dam and liter- 

 ally filled with larvse. 



Above the woolen mill is another dam, above which the water is pure 

 and sweet. The health officer ordered the gates hfted at this upper 

 dam and all the wrigglers were washed into Long Island Sound the 

 same day that thej^ were discovered. 



Howard, Dyar and Knab^ record a similar outbreak near Urbana, 

 111., where a creek is practically stagnant in late summer. At a certain 

 point this creek receives the waste from a slaughter house, and for some 

 distance below was so charged with decomposing animal matter that 

 no fish could live in it, though it contained millions of wrigglers of rain- 

 barrel mosquitoes. Adults covered the trees and bushes along the 

 banks, but their presence was felt only for a short distance, and few of 



1 The mosquitoes of North and Central America and the West Indies, Vol. I, 

 135, 1912. 



