THE CONQUEST OF THE MOSQUITOES 193 



But around the edge of Barro Colorado Island 

 the tall grass has begun to grow out into the water 

 from the shore. This breaks the force of the 

 waves and protects mosquito eggs and wrigglers 

 (Fig. 82). They could hatch in the more quiet 



After Howard and Herms 



Fig. 85. Egg, larva, pupa, and adult of 

 yellow fever mosquito — Aedes 



pools of the little island streams, and I found 

 them in the cups of water held at the base of the 

 thick leaves of some plants. 



Among the swarms appearing in the early morn- 

 ing and evening, I found both Aedes and Anophe- 

 les, as well as the more harmless mosquitoes that 

 are let alone because they do not carry either 

 disease. 



13 



