93 



Examine the bottoms of pools of polluted 

 water, and note in the mud the brilliant red 

 nymphs and lar.vae of Chironomus (Fig. 26). 



1. Observe that the Chironomus n3'mph has 

 a large globular body (head and thorax) and bears 

 a general resemblance to mosquito nymphs. 



2. Note, however, the presence of the con- 

 spicuous white feathery gills which form tufts at 

 the side of the head. 



3. Note that the Chironomus nymph and 

 larvae do not rise to the surface to breathe as do 

 those of mosquitoes. 



4. Note the curious rhythmic bending move- 

 ment of the larvae and nymph of Chironomus 

 which, when they are present in numbers, give the 

 mud at the bottom of the pool a curious appear- 

 ance. 



LITERATURE 



Mi all. Aquatic Insects. 



