Glucose and galactose are accumulated against a concentration difference by Streptococcus faecalis strain 10c1 which has been treated with iodoacetate to eliminate glucolysis. The rate and extent of accumulation are greater for glucose than for galactose but both processes show saturation kinetics, stereospecificity and sensitivity to metabolic inhibitors. Accumulated sugar does not exchange with glucose or galactose in the external medium. Loss of internal sugar is a relatively slow first-order reaction. Both accumulation and loss are temperature dependent. Preincubation of the organisms in arginine increases the rate and extent of accumulation and decreases the rate of loss. A model is proposed in which hexose accumulation results from an energy-dependent adsorption to specific thermolabile receptors.