234 SIR RUBERT BOTCE — THE PREVALENCE, DISTRIBUTION AND 



British Honduras, the Latin Republics of Central America, or the West 

 Indies. 



Yet it is well known that little importance has up till now been 

 attached to this very significant fact, and it is for this reason that I 

 publish in the present paper the results of my own observations and 

 investigations, 



I trust that this survey will bring home to the Medical Officer on the West 

 Coast the certainty that yellow fever is endemic, and that yellow fever must 

 be reckoned with, as long as the Stegomyia is the prevailing mosquito. I 

 hope, moreover, a further result will be that, just as in Tropical America and 

 in the West Indies, a concerted, well organised, attack will be made upon the 

 breeding places of this species of mosquito. As will be gathered from my 

 observations, this is not a very difficult or expensive task. It is eminently 

 practical, and, if properly carried out, will, lam convinced, show its beneficial 

 effect in a very greatly reduced sickness and mortality rate in the West 

 African Colonies. 



In this paper I have brought together the observations which I made when 

 on the Gold Coast, in Lagos (Southern Nigeria), and in Sierra Leone and the 

 Protectorate, and the records which I have been able to collect regarding 

 Dahomey, Togoland, the British Gambia, Senegal and other parts of Africa. 



II. Investigation of Breeding Places, 



I have learnt as the result of long experience that the only sure Avay'to 

 arrive at a correct estimation of the number and kinds of mosquitos present 

 in a town, is to make a systematic house to house inspection of all articles 

 containing water. For this purpose, it is necessary to have a block- or house- 

 plan of the town, and to divide the town up into sections, and then to work 

 over each section house by house. 



In specially printed note-books, divided into columns for cisterns, tanks, 

 barrels, tubs, wells, kerosene tins, ' odds and ends,' broken crockery, bottles, 

 and ^ other receptacles ' (as flower vases, lily tubs, etc. etc.), the number of 

 water-containers found is systematically entered, and a note made as to 

 whether Stegomyia larvse are present or absent. 



When I and my assistants (usually the Sanitary Inspectors) have made our 

 survey, all the odds and ends and discarded tins are collected together and 

 brought out into the street for the dust-cart to remove ; if larvae are found in 

 barrels or cisterns the water is emptied, or if that is impracticable, kerosene 

 oil is poured in; the occupier of the house is admonished and reasoned with, 

 and the sanitary inspector enters the name and address of the offender in his 

 book, and if the nuisance occurs again, action is taken. In order to discover 

 all the discarded tins etc., it is very often necessary to get the wild bush in 



