V. Memmler 1943 Perognathus californicus June 16, M.V.Z. Bad way for a while, but seems to have recovered now. Very little of the food I put in the box was eaten during the night, so they must have gotten out fairly early. Both mice took long stretches in the soil about 5:00 o'clock. They cleaned much in the manner of a cat using the front feet to brush the head and face; the hind feet were used to scratch the ear and other areas. This scratching with hind foot is done too rapidly for the eye to follow. The use of the front feet in cleaning is slow enough to be followed. June 17, Both mice were in the box this a.m. The box was a mess. Much digging had been done during the night and the food dishes were covered with soil. The green food left in the box was eaten. This was mallow and Melilotus. Some of the Meliotus was left, but the mallow was eaten. At noon I got some more soil to put in the box with the soil already present. I also added water to the mixture and tamped it down firmly in the bottom of the box. The mice at first did not know what to make of the new substrate and seemed to wander about the box aimlessly. My reason for putting in a former soil was so that the