Flies 



227 



quantity, and doubtless was laid by thousands of 

 midges. Figure 136 shows a little bit of it — a portion 

 of a few egg strings — magnified so as to show the form 

 and arrangement of the individual eggs. Such great 

 egg masses are not uncommon, and they foreshadow the 

 coming of larvae in the water in almost unbelievable 

 abundance. 



Fig. 135. A little hit of an egg mass of the midge, 

 Chironomus^ hung on water weeds {Philotria). 



Midge larvae are among the greatest producers of 

 animal food. They are preyed upon extensively, and 

 by all sorts of aquatic carnivores. 



Three families of blood-sucking Diptera have aquatic 

 larvae; the mosquitoes (Culicidse), the horseflies 

 (Tabanidae) and the black flies (Simuliid^) . Mosquito 



