118 MOSQUITOES 



vestig"atioiis in Africa, fouiid that tlic contents of the 

 intestines of the hirviT> arc mainly vegetabh' matter — in 

 some cases entin^ly so. Occasionally limbs of minute in- 

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

 quitoes or other ins(X'ts. " On watchiui;- them feeding- it 

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

 but many of them are rc^jected. 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 larva', both of Anopheles and C-ulices, but as a 

 rule living animals either esca[)(^ or are rejected." Chris- 

 tophers and 8tei)liens state that in their ol)servations in 

 Sierra Leone the food of the majority of the Anopheles 

 larvse seemed to be a unicellular protococcus. 



Length of Life of Adult Anopheles. 



Physicians studying the adults in order to d«^termine 

 tlu^ duration of the different stages of th(» malarial organ- 

 ism have occasion to keep adult Anoi)heles alive in con- 

 finement. This has been accomplished up to eight weeks 

 1)V feeding tlnnn occasionally upon sliced bananas or 

 otluu' fruits. The adults live for very considerable si>aces 

 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 trojucal 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 Immmi fi-tMpicntly 



