LIFE HISTOKIES AND STRUCTURE OF 



CULEX. 



The Culicidse for the most part prefer stagnant water 

 for their breeding places ; not, it is believed, for any ad- 

 vantages in the. food producing effect of such Miiter, but 

 because the enemies most dreaded by them are only 

 capable of prolonged life in fresher water. They have 

 been observed living in considerable numbers, in all stages 

 up to the imago, in a puddle of water, eight inches square 

 and one inch deep, made by the rain in an iron pulley in 

 a foundry yard. They are also to be observed teeming to 

 overcrowding in the hoof holes in boggy c©w pastures. 

 But the shallows occasionally overflowed and replenished 

 by rivulets in swamps, the stagnant pools formed by 

 ditches without outlets, and the vastly more numerous 

 murky pools made by the joining of tufts of grass in 

 marshes, are the usual breeding places in the rural dis- 

 tricts. In village and urban localities, rain tanks, un- 

 drained gutters, badly paved damp byways, and garden 

 ditches are the most fruitful places for recruiting their 

 numbers. These surroundings are selected by the female 

 with a view to the fact that from three to four weeks will 

 be required to perfect the changes from the egg to the 

 imago ; and they must be situated so as to receive suffi- 

 cient water from rain or outside overflow^ to replenish the 

 evaporation or soaking into the ground. In this selection 



(28) 



