periments carried on in the Campagna of Italy — for centuries 

 reputed one of the v/orst malarial regions of the world. Two 

 investigators lived here for weeks with the sole precaution of 

 retiring before sunset to a mosquito-proof hut and rem.aining 

 therein until after sunrise. The windows and doors remained 

 open and the notorious night air was never excluded. The 

 end of this experiment found the investigators in perfect 

 health. In this way it was demonstrated that the worst ma- 

 larial regions are robbed of their terrors by quarantine against 

 mosquitoes. That the mosquito was not unjustly accused 

 was proved by the placing of volunteers under perfect hy- 

 gienic conditions and allowing them to be bitten by mosqui- 

 toes which seven days before had fed upon m.alarial blood. 

 Malaria was invariably developed in these cases. 



Of many genera of mosquitoes Culex and Anopheles are 

 the most common. Now the malarial parasite may produce 

 its micro- and maerogametes in the intestine of any blood- 

 sucking insect, but it is only in mosquitoes of the genus 

 Anopheles ; that further development takes place. Since 

 Anopheles is a night-flier it is very natural that the malaria 

 was attributed to the night air when it should have been the 

 night mosquito. The bite of Culex never conveys malaria. 



The importance of the relation between the mosquito and 

 disease is further increased by the very recent discovery, 

 since 1899, of the transmission of the much dreaded yellow 

 fever by a mosquito, not Anopheles in this case, but Stegomijia 

 fasclata. This mosquito is not a native of this country, but 

 has been imported from the West Indies and Central America, 

 and has readily established itself in all our Southern coast 

 cities, even penetrating some considerable distance inland. 



The relation oi Stegomyia fasciata to yellow fever has been 

 demonstrated by experiments carried on in Cuba under the 

 direction of the United States army. A camp was established 

 under perfect hygienic conditions and here non-immune vol- 

 unteers were allowed to be bitten by mosquitoes which had 

 previously fed upon the blood of yellow fever patients. As 



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