54 Mosquitoes 



The spots available for multiplication of the in- 

 sects may be numbered ad infinitum. I have found 

 Psorophora and 0. triseriatus in hollow trees, Psoro- 

 pJiora also in pools, atropalpus in potholes in the 

 rocks along the Potomac and in hollows in the rocks 

 in swampy places, while in the swamp pools about 

 the rocks territans and Anopheles were breeding by 

 millions. It was noticeable that while there were 

 territans larvae in the rock cavities nibbling over the 

 dead leaves with the atropalpus, there were no atro- 

 palpus larvae in the ground puddles. In short it may 

 be said that mosquitoes will breed in any accidental 

 and transient water, in permanent pools, and in slow- 

 flowing streams where the banks are marshy, irregular, 

 and grassy, but not in swift streams or permanent 

 pools having clear-cut banks, especially if inhabited 

 by fish. 



