Abstract
This paper describes the use of cytochemical methods to demonstrate the presence of a polysaccharide-containing substance which is either a muco-protein or glycoprotein in the cytoplasm of plasma cells and reticulum cells and in the Russell bodies and in the Kurloff bodies of guinea pig lymphocytes. The Russell bodies in human plasma cells and the Kurloff bodies in guinea pig lymphocytes consist of a mucoprotein probably secreted by the cell.