Mosquitoes and 
io 
The four diseases which have now been definitely proved to be 
carried by these insects are Malaria, Yellow Fever, Elephantiasis 
and Dengue Fever; in addition there are some other cases in 
which mosquitoes are under suspicion. 
Mosquitoes and Malaria.— Through the labours of a 
number of investigators, of whom special mention must be made 
of Grassi, Laveran, Manson and Boss, the cause of this widely 
spread tropical and subtropical disease was shown, in the year 
1898, to be an intracorpuscular blood-parasite, which is invariably 
Pig. 3 .—Anopheles maculipennis , Mg. ?. x 4. 
The carrier of malaria in Southern Europe. 
carried from man to man through the medium of certain mos¬ 
quitoes. Further and more detailed work since that time tends 
to indicate that the different forms of malaria may be carried by 
particular species of mosquitoes, but this is not yet sufficiently 
established. Whether this be true or not, it has been proved by 
countless experiments that all the mosquitoes which are capable 
of carrying human malaria belong to a distinct group, the genus 
Anopheles; while even within this group there are many species 
which are not, or appear not to be, disease carriers. 
The Anopheles mosquitoes can be distinguished from the others 
