MALARIA AND MOSQUITOES 109 



be relied on, for Anophelines occur in the highlands 

 around both Freetown and Victoriaborg. The great 

 precaution is the exclusion of infected natives from 

 the immediate neighbourhood of the European 

 quarters, and it is believed that a distance of a 

 quarter of a mile from native huts would suffice to 

 protect against infected mosquitoes. As the evening 

 is the main time when the insects bite, business 

 could be transacted in the town during the day, and 

 the Europeans remove to the segregation area for the 

 evening. 



What are the chief mosquitoes that carry malaria? 

 The names of the various Anophelines seem to be in 

 a very confused state, and are still under revision. 

 In Asia they have been grouped roughly into four 

 classes, according to their breeding-places. The first 

 group seek open water where there is much aquatic 

 vegetation, the habitats favoured being ponds, lakes, 

 river-banks, and swamps. Two mosquitoes, Myzo- 

 rhynchus sinensis and M. barbirostris breed in such 

 places, and the first-mentioned has been proved 

 experimentally to be a carrier. The second group 

 are conveniently described as "stream-breeders," and 

 frequent strong-running streams with grassy edges, 

 and irregular ditches also furnish suitable breeding- 

 places. Three important carriers of malignant 

 malaria (tertian) haunt these situations namely, 

 Myzomyia culicifacies, M. listoni and M. Christopher si. 

 M. culicifacies is probably the most active carrier of 

 the malignant tertian parasite in India. The third 

 group of mosquitoes include those that frequent 

 clean pools with green algae, especially those left in 



