215 



2. Note the usual relation between the degree 

 of ill-health and the proximity of native huts. Make 

 a map shewing European dwellings and shewing huts 

 and hovels in relation with these (Fig. 70). 



3. Make a thorough investigation of the con- 

 ditions in these huts. 



(i) The percentage of infected children in each 

 group. 



(ii) The degree of infection of the adults. 



(iii) Roughly estimate the number of Ano- 

 phelines present, whether swarming, abundant, scanty, 

 or impossible to detect by search. In the latter case 

 make several ' test pools.' 



(iv) Determine the species present and the 

 relative numbers of each. 



(v) Determine the sporozoit rate for each 

 species. 



(vi) Carefully map all breeding-places, noting 

 what larvae are found. 



4. Capture as many Anopbelines as possible in 

 the European houses, especially in the morning, 

 and by looking within the nets. Determine the species, 

 sporozoit rate, and from where probably derived. 



In investigating the malaria of any such settle- 

 ment, native and European, continue the observations 

 if possible throughout the year. Make observations 

 on 



1. Seasonal variations in the endemic index 

 (percentage of infected children). 



2. Seasonal variations in the number of Ano- 

 -phelines at any time of the year. 



4. Distance of flight of Ano-phelines from breeding 

 grounds, etc. 



5. Sporozoit rate of Anophelines at different times 

 of the year. 



