118 MOSQUITOES 



vestig-ations in Africa, found tliat tlie contents of the 

 intestines of the larvae are mainly vegetable matter — in 

 some cases entirely so. Occasionally limbs of minute in- 

 sects or crustaceans were found, as well as scales of mos- 

 quitoes or other insects. " On watching- them feeding it 

 is seen that all minute particles are drawn to the mouth, 

 but many of them are rejected. This rejection is some- 

 what arbitrary, as a particle at first rejected is often 

 subsequently swallowed. Among the bodies seen to be 

 swallowed I have seen living- minute crustaceans and 

 young- larvae, both of Anopheles and Culices, but as a 

 rule living- animals either escape or are rejected." Chris- 

 tophers and Stephens state that in their observations in 

 Sierra Leone the food of the majority of the Anopheles 

 larvae seemed to be a unicellular protococcus. 



Length of Life of Adult Anopheles. 



Physicians studying the adults in order to determine 

 the duration of the different stages of the malarial org-an- 

 ism have occasion to keep adult Anopheles alive in con- 

 finement. This has been accomplished up to eight weeks 

 by feeding them occasionally upon sliced bananas or 

 other fruits. The adults live for very considerable spaces 

 of time, as has, in fact, been pointed out in the first chap- 

 ter of this book. In colder climates the adults hibernate 

 often in houses, and in tropical climates the adults live 

 through the dry spell to lay their eggs when the rains 

 come and breeding-pools are re-established. The hiber- 

 nation of Anopheles in this country has been frequently 



