RICE FIELDS AND MALARIA. 
By C. P. Kennarp, M.D., Ed., M.R.C.S., Eng. 
The connection of Malaria with rice-fields is no new theory, so long ago as 
1899 and 1900 Professors Celli and Koch laid great stress on the part the culti- 
vation of rice-fields plays in favouring the multiplication of mosquitoes, and 
Celli then observed that it is well known that the formation of rice-fields causes 
the re-appearance of malaria where it has become extinct, and where it already . 
exists they are a very active focus of production. 
It may, however, be of interest if 1 trace the connection between the two as 
shown in the colony, my observations being chiefly connected with the Coren- 
tyne Coast, which I have known intimately for years. 
That the anopheles is the carrier in the malaria-mosquito process of infection- 
is now so well known that it is unnecessary for me to dwell on it. What I propose 
is to trace the connection of the rice-fields with the anopheles and the anopheles 
with man. 
Of late years there has beena marked increase of malarial fever on this coast, 
coincident with the great extension of the rice industry there ; beyond this 
increased rice cultivation there has been little change, drainage, other agricul- 
tural pursuits, and methods of living remain much the same. This alone is 
suggestive of a connection, and it has evidently not escaped the lay mind for an 
old driver remarked to me sometime back, ‘“‘ Doctor, we never had so much 
sickness before the rice-growing was started as we get now.” 
The ordinary preparation of the land for rice-fields begins when the ground 
is covered with water, the people then cut down the bush and weeds, some of 
this is put at the sides of the plots to form meres, the rest is ploughed in, in new 
land some levelling off before the land is covered with water may be required, 
but practically, anyhow, after the first year allthe land is worked up under 
water ; the land is then planted up with the young rice and remains in this 
submerged condition until the rice is nearly ready to be cut, when the water is 
drained off, the land then dries rapidly and the rice is cut with the land usually 
in a dry condition ; the most desired condition of weather during the last period 
of the rice growth is that of frequent light showers, when this happens the land 
is not kept under water, as the rain is enough for the growth and favours the 
ripening, and if the rice falls to the ground, as it frequently does if high winds are 
on, itisno destroyed as it is when falling into the water ; this weather, however, 
is perhaps exceptional. To keep up the supply of water irrigation is required, 
this is more or less under control and when it is pumped in and out of the 
trenches, as on the estates, the supply can be better regulated than on other 
places which have to depend on gravitation from the savannah waters. Ifall the 
rice plots, ina field, or set of fields under the same irrigation and drainage, were 
planted up at the same time, the water supply could be much better regulated, 
