Anopheles Propagation Areas 57 



In the dry season pasturage is not good on dry 

 lands, and the owners of animals are then incUned 

 to turn them loose, or fasten them in low spots, 

 and near ditches. An active animal can spoil a 

 trained ditch in one night, and leave it in a condi- 

 tion to become the most prolific source of mos- 

 quitoes in the vicinity. This matter was found 

 to be so important that legislation became neces- 

 sary to keep ditches in proper shape. It is unlaw- 

 ful now for horses or cattle to be at large, or tied 

 in places where their presence interferes with 

 axiti- Anopheles operations and becomes a sanitary 

 nuisance. Even so, it is necessary to put up sign 

 boards along ditches and in places where animals 

 are not desired. When sign boards were first 

 placed on soft ground to notify people not to tie 

 animals in that vicinity, some poor ignorant 

 natives who could not read thought the sign posts 

 were excellent objects to which to tie their animals. 

 Night policing is stiU. essential to enforce the 

 ordinance. 



WHEEL TRACKS OF WAGONS 



On bad roads, not frequently used, the rut 

 marks produce Anopheles and Culex, but where 

 travel is frequent there are no larvae. Where 

 wagons pass through pasture land in the wet 



