FACTORS IN PLASMA CONCERNED IN NATURAL RESISTANCE TO AN AVIAN MALARIA PARASITE (PLASMODIUM LOPHURAE)

Abstract
The plasma of adult chickens, when injected into young chicks or chick embryos infected with Plasmodium lophurae, lessened the parasitemia. The substances responsible for this effect were inactivated or removed by the heating of adult chicken plasma for ½ hour at 65°C., followed by centrifugation to remove the coagulated material; but they were not affected by heating for ½ hour at 56°C. The active materials were present in the euglobulin fraction of hen plasma.