41 



MALARIA IN INDIANA. 



Primeval conditions. 



Ground covered by forest or lierbage, retention of moisture 

 or rain. 



Streams running, dear, full of fish. 



Coming in of the settlers. 



Destruction of the forest, periodical drying up of the small 

 streams. 



Destruction of fish, increase of mosquitoes. 



Advent of malaria. 



Absence of physicians and remedies — antiperiodics. 



Settling up of the country, malarial parasite more readily 

 transferred. 



Canal reservoirs and railway embankment ponds as factors. 



Drainage of wet pla<-es. fewer mosquitoes. 



Free use of quinine. 



Isolation of the sick and use of screens. 



Subsidence of malaria. 



No malaria in large cities, little in sul)urbs. 



Continuance of malaria in backward communities. 



