RESEARCH IN SIERRA LEONE. 183 



A road runs from Kent to Freetown along the coast, and on it are situated 

 several large and important towns, the chief of which are York and Hamilton. 

 Several creeks surrounded by mangrove swamp have to be crossed by canoe, 

 and at all of these G. palpalis was abundant. Reference to the map will show 

 some of the places at which captures were made. 



(11.) Freetown. 



Freetown has always had a bad reputation for mosquitos, but thanks to the 

 efforts of the Sanitary Department this stigma may now be partly withdrawn. 

 In 1911, Dr. D. Alexander took over the duties of Sanitary Officer for Freetown 

 and directed all his energies to the almost herculean task of abolishing these 

 insect pests. By means of a careful and systematic examination of the various 

 compounds and by a rigorous application of the mosquito ordinance, which makes 

 the presence of mosquito larvae in any compound a punishable offence, the 

 natives have been made more careful as to the water-containing receptacles in 

 their preserves. This work was carried on in the face of great opposition on the 

 part of the natives, and it will have to be continued in the same stringent manner 

 for some time to come if the benefit already achieved is to be maintained and 

 augmented. 



At my suggestion, Dr. Alexander kept and bred out some of the larvae 

 taken during his inspection, and also preserved many other sets of larvae which 

 he had collected as evidence in criminal charges. It is unnecessary to give the 

 details of the nature of the various receptacles in which these larvae were found, 

 as the most of them are now well known, nor would it serve any useful purpose 

 to give the exact localities where these were found, but it might be well to 

 point out the types of mosquito found in Freetown. 



By far the commonest and most widely distributed is Stegomyia fasciata ; it 

 may safely be said that this species bred out from over 90 per cent, of the 

 samples taken. The other species found include : — Stegomyia sugens, Anopheles 

 costalis, A. fanestus, Culex duttoni, C. invidiosus, C, deceits, and Culiciomyia 

 nebulosa. 



An examination of the area at Cline Town, which belongs to the Government 

 Railway, made by the writer along with Dr. Alexander, revealed a most 

 deplorable state of affairs. Lying about all over the compound were iron and 

 other utensils not in use, which served to hold small quantities of water. In 

 every collection of water examined mosquito larvae were found, and in every 

 case Stegomyia fasciata bred out from these. It should be borne in mind that 

 all water-holding vessels should be examined and emptied regularly, as one can 

 never be sure under what conditions Stegomyia may breed, e.g., the water which 

 was kept in the barrels used in the blacksmith's shop for cooling red-hot iron, and 

 which must necessarily become fairly warm at times, was found to contain larvae. 

 Materials used in railway construction, when piled up, in most cases formed 

 suitable places for the breeding of mosquitos, and if such is to be avoided there 

 is only one solution, namely, the storing of these under water-tight roofs. 



Apart from mosquitos, blood-sucking flies are practically unknown in Freetown. 

 Glossina palpalis occurs around Wilberf orce and Hill Station and I have also 

 32306 G 



