146 ANIMAL COMPETITORS 
straight down in a narrow shaft below the frost 
line, then turns and winds away horizontally, 
and as the tunnels are used year after year, 
with continual enlargements, old ones may 
reach to a great length, with branches and 
chambers accommodating several pairs, and 
secret exits. In the autumn one of the under- 
ground chambers is furnished with soft bedding 
and becomes the living-room of a family, while 
other chambers are stored with provender or 
set apart as receptacles for refuse. Now the 
chipmunk becomes exceedingly busy, fattening 
himself upon. the ripening nuts and seeds, not 
only, but upon many tuberous roots, mushrooms 
and green corn. On each side of his mouth, 
separated from it by thin partitions of muscu- 
lar skin, are large cavities or pouches, opening 
behind the teeth, which are as useful to him as 
are our baskets and wheelbarrows to us. He 
brings to the surface in them the material ex- 
cavated from the distant ends of his burrow, 
and after packing them full of seeds or nuts he 
returns to empty their loads—perhaps half a 
pint at a time—in one of his storehouses. All 
the ground-squirrels have such cheek-pouches; 
