SOP MOSQUITO LARVA AND FRESHWATER FISH. 
world always brings the risk of the accidental introduction of some 
other and undesirable organism. In the meantime it seems advis- 
able to fill up all large pools in the neighbourhood of the town, or, 
if this is not feasible, to clean them of all surplus vegetation, and to 
introduce into them small species of fish such as are known to feed 
on mosquito larvae, like the © Ikan mata lalat’”’ and especially the 
“ Tkan pelaga”’. 
However, there must be in a town like Singapore many locali- 
ties in which Anopheles and other mosquitos breed, and which are 
quite inaccessible to fish, and by far the greater area of the town 
would probably not be touched at all by preventive measures, such 
as the introduction of fish. If, as I know from my own experience, 
Anopheles, besides Culex and Stegomyia, may practically any day 
be found in a comparatively healthy part such as Fort Canning Road, 
then an attempt to exterminate malaria by means of fish in the 
crowded central districts of the town would be utterly hopeless. 
But the experiment might be of use in the outskirts of the town. 
I have the honour to be, 
Sir, 
Your obedient servant 
R. HANITSCH, 
Director. 
Jour Straits Branch 
