Saphenous veins were taken for examination: unchanged, varicose with thrombophlebitis and varicose thrombus. The contents of haemoglobin and protein were determined in the homogenate of that material. Only small quantities of haemoglobin were found in walls of unchanged veins. Greater amounts of haemoglobin were observed in walls of varicose veins, especially in walls of varicose veins with thrombophlebitis. The varicose vein thrombus also contained marked quantities of haemoglobin.