Anopheles Propagation Areas 67 



difficult to account for the presence of mosquitoes, 

 and more distant production areas, winds, etc., 

 may wrongly be held responsible for a temporary 

 influx. Seepage may be found at most unexpected 

 places during or after long rainy periods; it almost 

 invariably produces mosquitoes, and in many 

 cases may not be noticed until some adults have 

 been produced. Nearly all seepage outcrops as 

 well as areas flooded by seepage water were covered 

 by the same class of vegetation that grew above 

 the outcrop, and there was nothing to denote their 

 presence. One cannot appreciate the number of 

 mosquitoes produced by even small seepage out- 

 crops without actually inspecting them. 



LAGOONS, LAKES, PONDS, ETC. 



Many parts of lagoons in the tropics are impass- 

 able and trochas or paths have to be cut through 

 the heavy growth to penetrate some parts of them. 

 Examination, or mosquito inspection, when the 

 bottoms are soft deep mud is tedious but interest- 

 ing, and the splashing of an occasional alligator 

 removes any sense of monotony. It is surprising 

 how many of these areas do not produce mos- 

 quitoes although conditions as to food, protection, 

 etc., seem to be ideal. After examining many of 

 this character the observer is apt to take it for 



