‘GROUND-SQUIRRELS 151 
western group includes the rock-squirrels, 
which are never seen far from cliffs or broken 
ledges. Bailey tells us that they climb the trees 
for acorns and berries, but when surprised al- 
ways rush to the ground and scamper away to 
the nearest rock-pile. They are extremely 
wary. ‘‘Like most of the smaller ground- 
squirrels of the arid regions they usually bur- 
row under a cactus or some low thorny bush, 
where they obtain shade and the protection of 
thorny cover. They apparently do not hiber- 
nate, but during the cold weather have the un- 
squirrel-like habit of closing their burrows and 
remaining inside, as a protection against en- 
emies, and especially snakes. ows a, dale 
other members of the. genus, these ground- 
squirrels feed on seeds, grain, fruit, green 
foliage, _ lizards, and numerous insects, and 
often gather around gardens and green fields, 
where they do considerable damage in spring 
by digging up corn, melons, beans and various 
sprouting seeds, and, in summer and fall, by 
feeding on the ripening grain.”’ 
Squirrels and bubonic plague. _One of these 
ground-squirrels, that most common in central 
