(The material from two of the cases of blackwater fever was obtained through the kindness of Dr. Andrew Connal, Director of the Medical Research Laboratory, Lagos, Nigeria.)
The incidence of jaundice among cases of malaria varies considerably in different districts, dependent in part upon the type of malarial parasite, the virulence of the infection, and the susceptibility of the individual. In Nigeria I had the opportunity of observing a considerable number of cases of acute sub-tertian malaria, accompanied by jaundice in the native and a few in the white population. The severe acute malaria in the native occurs chiefly in childhood, and although the infection is not infrequent in adults the disease is not so commonly of the severe variety. The adult community possesses an acquired immunity. The white population consists of adults only, and these arriving as non-immunes require a varying period of years to demonstrate a resistance of any value.