REPORT ON MOSOUITOES. 



MAIvARIA. 



It was at first intended to include in the scope of the investiga- 

 tion a study of the malarial parasite and a series of experiments 

 with miosquitoes that had fed upon the blood of malarial patients. 

 To make th.ese studies and experiments Dr. Herbert Parlin 

 Johnson, then of Cambridge, Mass., who had had special train- 

 ing along these lines, was engaged during the summer of 1902. 

 By the courtesy of the Board of Health at Harrison, a room in 

 its building was assigned to Dr. Johnson, and a series of obser- 

 vations and experiments was begun. As the season advanced, 

 however, it became obvious that far greater facilities were needed 

 than the money in hand could secure, and further, that such 

 experiments must be carried on in direct connection with a public 

 hospital. As this phase of the subject was also engaging the 

 attention of medical students and investigators, this line of work 

 was abandoned. Dr. Johnson's work appears in my Report for 

 1902 and the acount of the malarial parasite and its development 

 given elsewhere in this w^ork is practically as prepared by him. 



EXPERIMENTS. 



It is impossible in any report of reasonable size to cover all the 

 experiments made, in any detail. So many suggestions have 

 been received and so many assertions were made in print, either 

 as news reports or as advertisements, that it was necessary to 

 test a great number lest in rejecting- all, some really good things 

 be missed. Many hours of patient work and watching and many 

 pages of notes are recorded by a line or a word, or not at all, 

 simply because the results were negative. It is easy to make 

 a positive asertion, as, for instance, that in the migrating sollici- 

 tans female, ovaries do not develope; but it required the exami- 

 nation of several hundreds of specimens from widely separated 

 localities to make it safe to speak so positively. It is the result 

 of the work that is demanded,- and which is given with just 

 enough record of the observations and experiments made to show 

 that it rests upon more than a bare assertion or belief. 



ASSISTANTS. 



In an investigation covering so great an area, when it is 

 imperative that at one date several localities shall be under 

 observation, no one man can do all the work. The one in charge 



