Hydroxyethyl is a waxy or branched starch which has been hydroxyethylated to retard intravascular hydrolysis. It is presently under consideration for use as a plasma expander. Previous studies with this starch have dealt mainly with its pharmacologic and physiologic properties in the normal and hypovolemic animal. Its therapeutic efficacy in hemorrhagic shock appears to be equal to or greater than clinical dextran, the present most commonly used plasma substitute.1(Clinical dextran is the term used here to refer to dextrans used by various investigators, and which are the subjects of the reports included in the listed references. There is a considerable range in molecular weight of these products; for specific information relative to each dextran mentioned, see the pertinent reference.) Dextran (average molecular weight from 40,000 to 80,000), is strongly antigenic for both man and animals.2,3Hydroxyethyl starch is also a high-molecular-weight polysaccharide, and if it is to