THE increasing use of dextran solutions as plasma substitutes has made the problem of the fate in the organism of the injected polysaccharide a very important question. Several studies on this problem have been carried out by means of chemical and serological methods of determination of dextran in extracts of tissues1, and a few histological investigations are recorded in the literature. The methods used in these studies are, however, inadequate, as they do not allow any conclusions to be drawn as to the nature of the deposits found in the tissues after injection of dextran.