The effect of decerebrate rigidity and prolonged general anesthesia upon the lactic acid content of the gastrocnemius muscle (cat) was observed. It was found that the blood lactic acid level of decerebrate cats is higher than that of normal resting ones. This was found not to be solely an ether effect. In 10 of 14 experiments, the lactic acid content of the tonic gastrocnemius was higher than that of the atonic one in the same animal (the muscle made atonic by-section of the sciatic nerve on one side). The glycogen content of the tonic and atonic muscles was essentially the same. In 6 of 9 experiments, it was slightly higher on the atonic side. In cats under general ether anesthesia, the lactic acid level is initially high but tends to drop as the anesthesia continues. Furthermore, the glycogen con-teat of unstimulated gastrocnemii of the rat and guinea pig does not decrease under amvtal anesthesia of 3 1/2 hrs. A sweeping conclusion that the glycogen content of unstimulated mammalian muscle decreases during general anesthesia is unjustifiable.