kind is often packed
in tightly against the other, but with a very abrupt change in the
character of the material.

A number of the more interesting and representative results of the
weighing and analyses of burrow contents are presented herewith in
tabular form. The data for each den, or lot, shows in grams the quantity
of stored material removed and the best estimate it was possible to make
of the percentages or weights of the various species. When the weight
was less than 5 grams, the mere trace of the species frequently is
indicated in the following tables by the abbreviation "Tr."

TABLE 1.--_Analyses of plants stored by _Dipodomys spectabilis
spectabilis_ Merriam, obtained from examination of representative dens
(all except Den 24 from U. S. Range Reserve, near the Santa Rita
Mountains, Ariz.)._

DEN 1.

February 7, 1918. Burrow typical, located on bank of wash in partially
denuded grass-land, _Bouteloua rothrockii_ and weed type; soil sandy;
burrow photographed in section (Pl. VII, Fig. 1).

Species stored. Grams.

Bouteloua rothrockii 2,205
Bouteloua aristidoides (B. eriopoda and B. rothrockii, Tr.) 1,445
Plantago ignota 442
Eriogonum polycladon 35
-----
Total 4,127

Four species of plants represented in burrow contents (Pl. VII, Fig. 2).
Maximum quantity for single burrow in series of 22 from Range Reserve.

DEN 2.

March 9, 1918. Surroundings overgrazed and partially restored by
complete protection. Red soil, with much coarse rough gravel and stone.

Species stored. Grams.

Bouteloua rothrockii (nearly pure) 1,460
Bouteloua rothrockii (mixed with Aristida spp.) 945
Boerhaavia wrightii 660
Bouteloua rothrockii }
Bouteloua aristidoides } 525
Aristida divaricata }
Aristida bromoides }
Kallstroemia laetevirens