45 



be possible ; because in the first place there will be no one 

 to direct them, and in the second place there will be no one 

 to pay for them. I fear that we shall generally have to 

 leave small native towns and villages to their fate for the 

 present, unless there is a much more marked advance of 

 civilization than we can observe at present, or unless some 

 one comes forward to provide the money required. 



(4). Travellers* Camps. Unless the camp is intended to 

 be permanent and labour is abundant, it will generally be 

 waste of time to drain the surrounding area. 



21. Where to start Mosquito Brigades. 



(i). Isolated Houses where the pools are few and labour 

 is abundant, and where white men live. 



(2). Plantations, Mines, and Farms where white men 

 live and labour is abundant. 



(3). All Settlements where white men live in any num- 

 bers. Especially Large Towns. 



Considering these principles, we shall observe that it 

 will generally be advisable to start a campaign against 

 mosquitoes wherever the game is worth the candle. The 

 expense of draining a square mile of country may be just 

 as great when that square mile contains one house as 

 when it contains a thousand. But in the first case the 

 expense will be incurred in order to protect only one 

 house ; in the second case in order to protect a thousand. 

 Hence we arrive at the following general rule: The 

 greater the density of the population the greater the necessity 

 for measures against mosquitoes. 



Other points to be taken into consideration are the 

 relative importance of the locality, the presence of industrial 

 institutions, governments, soldiers, railway centres, and so 



