Many kinds of plant gums are contained extensively in vegetable foods and fodders. Their nutritive properties have not, however, been thoroughly investigated yet, and their nutritive values have been generally considered to be inferior to those of starches and sugars for every species of animal. Recently Furth and Engel have reported that rats could store only negligible quantity of glycogen in their livers when fed on the cherry gum or tragant gum. The present work has been undertaken to see if any fat and glycogen can be accumulated in the bodies of rabbits when gum arabic was given to them as an example of the plant gums, and to determine the amount of each, if any.