Proceedings of Eighth Annual Meeting 91 



gested than has been suggested in the address just preceding. We 

 would like to hear from Dr. Headlee. 



Secretary Headlee : Very shortly after 1912, when the mos- 

 quito work was taken up on a wide scale, the necessity of measuring 

 results of mosquito work in some definite way was realized, and the 

 rule finally adopted is now known as the night collection method. 

 The method referred to has been published already in at least one 

 bulletin of the Experiment Station and I think has been repeatedly 

 mentioned in the proceedings of this association. 



There are factors that have to be evaluated. Almost every species 

 of mosquito with which we deal requires a little dififerent method of 

 collection to get results that are readable and comparable. I asked 

 Dr. Hoffman concerning the evaluation of the factor of the collector ; 

 assuming, of course, that the collectors are faithful in the perform- 

 ance of their duties. That must be assumed before you can get 

 anywhere and it must be a fact. 



Now assuming that you must evaluate the value or determine the 

 value of that factor not only as a collector but as an attractor of 

 mosquitoes. There are men, and we have had them in our organi- 

 zation, that do not attract mosquitoes, men whom mosquitoes such 

 as we have in New Jersey will not bite. Now that must be deter- 

 mined. You must evaluate the attractiveness of your collectors. 

 You must evaluate the speed, mechanical, manual speed or celerity 

 of the collectors; because one man, by reason of quicker move- 

 ments, will collect twice as many mosquitoes under the same condi- 

 tions as the fellow who is slower. 



You must evaluate the nature of your collecting places. You can- 

 not compare collections taken on a street corner with collections 

 taken in shrubbery. You cannot compare collections taken in a low 

 lying gully, where there is a lot of moisture, with collections taken 

 in the same neighborhood on top of an adjacent hill. 



You must evaluate a number of other . factors. You must eval- 

 uate the time of the day when the collection is made. You must 

 evaluate the temperature. You must evaluate the atmospheric mois- 

 ture to get these collections sufficiently comparable to read them as 

 reliable data. You must evaluate wind movements. A collection 

 made on the windward side of a patch of shrubbery will be entirely 

 different from a collection made on the leeward side. 



Now all those things must be taken into consideration. Our 

 experience has shown that and we have had these night collection 



