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latter part of June, July and the first half of August are the months 
with few cases. Occasionally it has happened that we have seen 
no cases for four to six weeks, and consequently our experimental 
work has been seriously hampered. From September to January the 
cases appear to increase gradually ; February and March may show a 
fall, and the number may continue to fall or rise again in the latter 
part of May. 
The source from which the female Stegomyia obtains her infection 
is the labouring-class foreigner and the native child. 
We deplore the custom of the laity in attempting to treat cases 
of fever occurring among their friends and relatives. The Portuguese, 
Italian and Spanish nationalities form the preponderating foreign 
labourer class in Manaos, and therefore they are the greatest offenders. 
Should a foreigner, especially a new comer and non-immune, 
exhibit malaise, headache, pain in the back and lower limbs, a 
tendency to nausea and some fever, all early symptoms of the disease, 
instead of calling in a doctor to diagnose and treat the case, home 
remedies are given. Sometimes a purge is taken, but unfortunately 
it is not generally administered ; food is not withheld, and the patient 
may force himself to eat the most unsuitable food for one in bis 
condition; a sharp mustard plaster to the calf of each leg is applied 
and kept on until large blisters are formed. 1 his is supposed to be 
an excellent remedy, and is almost universally used. The patient 
may lie in bed or attempt to go about his work; in any case he is 
unscreened and exposed to the bites of the hungry Stegomyia—thus 
during the first few days of his illness, the only period of the disease 
at which he is a source of infection, he serves to nourish and infect 
the numerous Stegomyia which have taken up their abode in his 
surroundings. 
As the disease progresses and the symptoms become more and 
more defined, his condition becomes worse, and a doctor is called in 
at the end of the third or fourth day. Of what use is it to screen him ? 
The period of infection is passed, his blood is no longer infective, the 
appetite of the Stegomyia is already satiated. Probably the first 
three days of the disease are completed: the days which are so 
important for the doctor, for it is the management and treatment of 
a yellow fever patient during these three days which materially 
influence the ultimate result. Of what use is it to call a doctor or to 
c 
