The stroma forms only about 10 per cent, of the solid parts of the corpuscles, the rest being haemoglobin. The proteid basis of the stroma is probably made up of a globulin, also containing lecithin, cholesterin and fats in minute proportions. There is little more than one-half per cent, of inorganic salts in the red blood corpuscles, of which more than half consists of potassium phosphate and chloride.