cKaye - 1933. Santa Cruz, Cal. - Dec. 8, 1933. The tremendous number of unoccupied perognathus (particularly monatus) holes down in Walker Basin are an indication of a change in conditions there during the last year. Deserted badger holes also point to these recent changes. The heavy snows last winter were probably chiefly responsible for the migration of the pack rats to the canyon and basin bottoms. These snows may also be responsible for the shortage of perognathus monatus. These mammals being the smaller, and consequently less able to survive such strenuous conditions and consequent competition as there must have been. It is even possible that the perognathus lived in danger of predacious attacks by other mammals. The poison campaigns account for the shortage of both species and individuals at French Gulch. We took no dipodmys there, and the fact that they were there is proved both by the tail found by Stilmore, and by the verbal assurance of the