IN a previous paper(1) we found that the total number of leucocytes in the circulating blood rises during digestion and reaches a maximum in about four hours after food. This leucocytosis is not affected by removal of the spleen. The increase comprises a lymphocytosis and a polymorphonuclear leucocytosis but the eosinophils show very little change. The number and varieties of white cells in corresponding mesenteric veins and arteries during digestion are similar, and resemble those in the general circulation.