14 THE YELLOW-FEVER MOSQUITO. 
Etiology and Prevention of Yellow Fever,” published in 1890. But 
a claim made by Sanarelli in June, 1897, for a bacillus which he 
found in 58 per cent of yellow-fever cases, and which he called Bacillus 
icteroides, received considerable credence. This was found afterwards 
by several investigators in considerable abundance, but later it was 
shown by Reed and Carroll that the organism in question is identical 
with the bacillus of hog cholera and is in no way concerned with 
yellow fever. 
In 1881 Dr. Carlos Finlay, of Habana, proposed the theory that 
yellow fever, whatever its cause may be, is carried by means of a 
certain mosquito from man to man. His original paper shows that 
he had carefully studied the habits of house mosquitoes and had 
determined all of the factors in the life history of the species now 
known as the true yellow-fever mosquito, which have since been 
shown to be essential in its role of transmitter of the disease. It was 
this careful study of the mosquito and the disease, conducted through 
many years in the most favorable locality, the city of Habana, that 
gave him a firm conviction that the two were interdependent. On this 
account his theory has true scientific merit. It was based on intensive 
study, and not, as had been the case with his predecessors, on vague 
suspicions. Subsequently he published a number of important papers, 
in which his views were modified from time to time. He thought out 
carefully the question of immunization and concluded that this might 
be brought about by mild infection through the bite of a single mos- 
quito. In one of his papers he published experiments with 100 indi- 
viduals, producing 3 cases of mild fever. None of the cases, however, 
was under his full control; and as the possibility of other methods of 
contracting the disease was not excluded, his claims were not accepted. 
In 1900 the facts were determined by scientific methods. An 
American army being at that time stationed in Cuba, a medical board 
was appointed by Surg. Gen. Sternberg for the purpose of inyves- 
tigating the acute infectious diseases prevailing in the island. The 
board consisted of Walter Reed, James Carroll, Jesse W. Lazear, 
and Aristides Agramonte. Dr. Reed was the chairman of the k2ard. 
In the course of the work yellow fever naturally received the main 
measure of attention.. The claims of Sanarelli’s Bacillus icteroides 
were disproved, and Reed and his associates began a careful and 
thoroughly scientific investigation of the possibilities of mosquito 
carriage of the disease. Experiments carried on by the board were 
as perfect in their methods as it was possible for scientific acumen 
and hard common sense to make them. -Every possible element of 
error seems to have been guarded against. The final and conclusive 
tests made during the autumn of 1900 were conducted with a spirit 
of earnestness, self-sacrifice, and enthusiasm which affected everyone 
BAT 
