propagation of Cellia albimana, caused by the numerous indentations 
of the Rio Negro and the Igarape da Cachoeira Grande. Malaria 
exacts a heavy toll from the residents of this district. 
The suburbs of Sao Raymundo (Plan 23) and Colon: 1 
Machado (Plan 24), on the far sides of the Igarapes Cachoeira Grande 
and Cachoeirinha, are on fairly high ground, but many ravines and 
swampy low-lying areas exist. The majority of the houses are 
situated along and in these areas. 
Further outside the limits of the city, very extensive sw imps 
occur. Unfortunately these, districts are thickly populated by the 
poorer class, with a few residents of the better class. Near the old 
pumping station of the waterworks (Plan 21), the Bosque (Plan 2:), 
Pensador (Plan 27) and Flores are a series of swamps which exist 
all the year round, and during the rainy season cover very extensive 
areas. From every one of these swamps larvae of Cellia albimana, 
Cellia argyrotarsis, Culex fatigans, Mansouia ti/illaus, and UrtM 
taenia geometrica have been taken, and adult specimens captured in 
the houses of the inhabitants at the Bosque, Pensador and Flores 
Numerous Stegomyia calopus have been found in the larger houses 
where rain-tubs and barrels are kept unscreened and full of water. 
The Bosque, Pensador and Flores are prolific breeding places tor 
Anophelines, and the residents in these localities suffer from malaria 
I he residents of these districts are responsible for many of the 
breeding-places, as they are too indifferent to fill up any of the 
shallow pools or to dig small trenches to drain the natural hollows. 
In these localities (Plan 22) much sand occurs which is used by the 
local builders; as a consequence extensive sandpits exist, which, 
during the rainy season, are full of water, and serve as breeding-places 
or both Culicines and Anophelines. Such foci occur all along the 
swamps and near to the houses. It is therefore not astonishing to 
find so many cases of malaria in proportion to the number of the 
inhabitants. 
We fully realise the desire of the authorities to stamp out malaria 
“to be d tr Mana ° S ' of - ^ady been or 
reaefetfTeV 0 ^^ bC aC “ m P ,ishcd by attacking the upper 
Bicf The «inf 7 th B ' ttenCOUrt ' Tocos, S. Vicente and 
hC fillmg ° f th6Se ^ ra P fe be gradual, as their extent 
