The % of glycogen in the leg muscles of eviscerated spinal cats is not affected by injecting glucose intravenously over a period of 2-3 hrs. It is increased when glucose is injected with insulin. It also increases when glucose is injected without insulin into non-eviscerated spinal cats. The pancreas is responsible for these differences, as glucose in depan-creatised spinal cats causes no glycogen formation in the muscles. Epinephrin does not stimulate the breakdown of muscle glycogen, nor does it give rise to hyper-glycemia in eviscerated cats.