Arizona \_ 
Exp. Sta. / 
LIFE HISTORY OF THE KAXGAROO RAT. 
31 
storage. The chaff refuse from the food probably contributes largely 
to it, though some leaves of grasses not stored for food may also 
be found, and a nest, especially the one in use, may be distinguished, 
if excavating is carefully done, by the distinct cavity about the size 
Kig. 3. — Diagram of the system of surface runways and subsidiary dens of Dipodomys 
spectabilis spectaHHs. The underground tunnels of the main den were too complicated 
to illustrate on this scale, being very similar to those of Figure 2. The underground 
tunnels of the subsidiaries are shown in solid black. Some runways fade out in the 
grass in a manner that can not be indicated in a line drawing. 
