128 MOSQUITOES 



and its seven non-ininiune occupants during' a period of 

 sixty -three days was an absolute failure ; all seven were 

 released from quarantine in excellent health. 



A precisely similar building was erected at Camp La- 

 zear, which was known as the infected mosquito building. 

 The door and windows were placed on opposite sides of 

 the building so as to give a thoroug'h ventilation. It was 

 divided into two rooms by a wire screen partition extend- 

 ing- from floor to ceiling. All articles admitted to the 

 building were carefully disinfected by steam before be- 

 ing placed therein. Into the large room of this build- 

 ing mosquitoes which had previously been contaminated 

 by biting yellow-fever patients were admitted. Non- 

 immunes were j)laced in both rooms. In the room in 

 which mosquitoes were not admitted the experimentalists 

 remained in perfect health. In the other room six out of 

 seven persons bitten by infected mosquitoes came down 

 with yellow fever. In all, of persons bitten by infected 

 mosquitoes that had been kept twelve days or more after 

 biting yellow-fever patients before being allowed to bite 

 them, eighty per cent, were taken with the disease. 



The conclusions reached after this careful experimen- 

 tation, have been summarized under eleven heads, as 

 follows : 



1. The mosquito — C. fascidtas — serves as the intermedi- 

 ate host for the parasite of yellow fever. 



2. Yellow fever is transmitted to the non-immune indi- 

 vidual by means of the bite of the mosquito that has 

 previously fed on the blood of those sick with this dis- 

 ease. 



