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The study of distribution of C. pipiens raised a question in 

 the writer's mind as to whether such studies could not be utilized 

 to test the efficiency of the practical work of control and to aid 

 it by means of pointing- out where special attention was needed 

 in time to prevent the emergence of a serious number of mos- 

 quitoes. While temporarily in charge of the practical work in 

 the City of Passaic in the late summer of 191 4, an opportunity 

 was afforded to give this idea a test. Collections of mosquitoes 

 on the wing were made regularly twice a week in the evening, 

 and were arranged in such fashion through the city as to give a 

 notion of the density. At no time did the density show a con- 

 tinuous distribution, such as was exhibited by the collections in 

 South Newark and North Elizabeth, while at all times the dense 

 spots were found to be separated. The writer instructed the 

 inspectors to look after the breeding places in these areas of 

 density with utmost care and to eliminate all breeding which 

 they could find. Invariably this resulted first in the finding of 

 unsuspected breeding of the house mosquito and its elimination, 

 and second in the prompt reduction of the density to the normal 

 status. It was found that prompt attention to these areas of 

 greater density resulted in the prevention of the emergence of 

 a serious number of house mosquitoes. Following this experi- 

 ence the method was recommended for use in other counties, 

 and has met with decided success as a method of checking up 

 the efficiency of the work and with more or less success as a 

 method of finding and reducing the unsuspected breeding in 

 time to prevent the nearby householder from being troubled. 

 It is the writer's belief that the devotion to and the faithful 

 practise of this plan would go far toward increasing the efficiency 

 of present fresh-water mosquito control. 



It was in Atlantic County that a need for a special study of 

 the migration of the salt-marsh species arose, because, unlike 

 the situation in the northern part of the State, the area of marsh 

 within the limits of Atlantic County was SO' large that it could 

 not all be controlled in less than a period of years, and none of 

 the marshes adjacent to Atlantic County could be ditched until 



