III. ENDEMIC MALARIA IN THE GAMBIA 
The discovery, both by Professor Koch in German East Indies, and by the mem- 
bers of the Royal Society Malaria Commission in West Africa ( 1 900), of the prevalence 
of malarial parasites in the blood of native children in an endemic area up to twelve 
years of age has given us a method by which a correct estimation of the presence and 
the extent of malaria in a district can be ascertained by the systematic examination of 
the blood of the children. 
While in the Gambia I obtained some one hundred and thirteen children from 
o to 1 5 years of age for examination ; the children were chiefly from the town of 
Bathurst and a native town seven miles away at Cape St. Mary ; a few were also 
available for examination at a small Mandingo town, Baia, one hundred and eighty- 
five miles up the river. At Bathurst the children examined were those who came to 
the out-patient department to be treated for various ailments, or were brought by 
their mothers, who had come themselves for treatment. Fourteen in all were obtained 
in this way, only one of them showing signs of fever (ioi*8°) at the time of examina- 
tion ; some were treated for worms, bronchitis, or injuries. The remainder of the 
children examined were those who came to be vaccinated at the house of the Public 
Vaccinator, Dr. Taylor ; they were, to all appearance, in good health. At the Cape 
and Baia the children were brought to me by their parents. The blood of many of 
the children at Bathurst was examined in the fresh condition, as well as by means of 
smears made in the usual way on a glass slide ; all the smears were stained by a 
modification of Romanowsky's method, recommended to me by Dr. MacConkey. 
From the table (No. I) given below it will be seen that eighty per cent, of 
the children examined harboured malaria parasites in their blood, 
and these occurred in children practically equally up to ten years of age (the num- 
bers are too small to give correct percentages at the various age periods). After ten 
years of age, out of thirteen cases examined seven were found infected ; in these cases 
the malaria parasites were rare in the blood ; in fact, in all except in one case, the 
parasites encountered on the films were very few. 
