X, B, 3 Barber et al.: Malaria in the Philippines 219 
ities, although in most cases the spleen index is higher. If we 
make a list which includes only children of whom both blood 
and spleen were examined, and which includes only one exam- 
ination of each locality, we have: Examined, 3,686; positive for 
parasites, 278 or 7.5 per cent; spleen enlarged, 458 or 12.4 per 
cent. These figures best represent the ratios between the two 
indexes. In nearly all towns where some positives for parasites 
were found the spleen index was higher than the parasite index, 
and many towns show a positive spleen index where the parasite 
index is 0. 
In 314 cases positive for malarial parasites and of whom spleen 
examinations were also made, 164, or 51.4 per cent, showed an 
enlarged spleen. Of approximately 569 cases presenting enlarged 
spleens of whom the blood was examined, 164, or 28.8 per cent, 
were positive for parasites. It is well known that cases ex- 
hibiting splenomegaly, known to be the result of malaria, often | 
fail to show parasites in the blood. 
The percentage of parasite-positive cases among spleen-neg- 
atives is of comparatively little significance in our series of 
examinations taken as a whole, since our list includes so large 
a number of nonmalarious localities. If we include only com- 
munities in which at least one parasite-positive was found, we 
have what is probably a fairer estimate. In these communities 
approximately 1,883 spleen-negative cases were found of which 
144, or 7.7 per cent, were parasite-positive. Only children are 
included and only those of whom both spleen and blood exam- 
inations were made. 
The important question comes up as to whether a spleen index 
of considerable magnitude indicates a present or recent preva- 
lence of malaria in a locality. 
Ross, Christophers, and Perry * have recently expressed the 
belief that the spleen rate is the “most readily and extensively 
applicable, and at the same time the most reliable measure of the 
amount of malaria in a community” with a serious qualification 
in the fact “that other diseases than malaria, very notably kala- 
azar, produce splenic enlargement and may, to an unknown 
extent, modify or even seriously interfere with the value of the 
figures obtained.” These authors examined 469 children of 
London and found only about 1 per cent with enlarged spleens. 
Only about 1 per cent of cases were found in which the question 
of enlargement was doubtful. They conclude that with the 
* Proc. Third All-India Sanitary Conf. Lucknow. Jan. 19-27, 1914: 
Supplement to Ind. Journ. Med. Res. (1914), 4, 15. 
