Hey INSECTS AND DISEASE 
been made under rigorous scientific conditions, it could 
not be proved that the mosquito had actually conveyed 
the disease. Eleven other experiments similar to that on 
Carroll were made; of these nine were negative, two positive. 
The negative experiments might be explained in several 
ways. The cases of yellow fever through which the mosquitos 
were infected were very mild, and the infection might not 
have been sufficiently virulent; or the interval between 
the two bites might not have been the right one. The 
positive experiments could not be explained away. A 
prima facie case for the mosquito as the intermediate host 
for yellow fever had been made out. 
It remained now to subject the mosquito theory to 
a fresh trial on a larger scale and under rigorous conditions. 
Forunately for the commission, the then military Governor 
of Cuba, Major-General Leonard Wood, was an officer 
formerly in the medical service, and his scientific training 
enabled him to comprehend the nature of the experiments 
proposed, and to appreciate their importance. It is the 
common fate of scientific investigators to be misunderstood, 
and to find their work starved by the false economy, or 
thwarted by the interference of high government officials. 
In this instance, however, every assistance required was 
liberally furnished. An isolated camp was established, 
volunteers from the U.S. Army were called for, and offered 
themselves freely, though fully informed of the risks that 
they would run. One cannot refrain from noting the very 
high courage shown by those who thus voluntarily risked 
their lives in a campaign more calculated to inspire fear 
than many military operations. Those in the camp were 
subjected to strict quarantine, so that the possibility of 
accidental introduction of infection might be excluded. 
The pulse and temperature were taken thrice daily, so that: 
any that might be incubating the disease should be at once 
detected, and this was continued until they had passed 
the full period of incubation of yellow fever, without 
developing any symptoms. Two buildings were erected 
in the camp, of similar size and construction, except that 
one known as the “ Infected Mosquito Building,” was 
divided in the middle by a permanent wire screen partition, 
and was well ventilated. The other known as the “ Infected 
