The Mosquito Must Go 



23 



A study of salt-marsh vegetation shows : 



i . That on areas on which by reason of lack of drainage 

 water stands on the surface for considerable periods, 



AREA OF OSISIHAL 

 SALT MABSH MOSQUITO 

 INFESTATION ENCLOSED BY 



BROKEN LINE . 



TIDAL MABSH UNDRAINED S 

 TIDAL MABSH PABTLY OB 

 COMPLETELY DBAINEO m 



ABEA PBACTICALLY FBEED OF 

 SALT MARSH MOSQUITOES il-i 



ABEA STILL INFESTED BY 

 SALT MABSH MOSQUITOES 3 



Fig. io. Progress of Saia-Marsii Drainage and its Effect on the 

 Mosquito Pest 



nearly all vegetation is destroyed and only pickle weed 

 can grow. 



That on areas on which the water stands for only a short 

 time but which have a water-logged soil, only coarse 

 grasses grow. 



