(8) Dipodomys s. spectabilis is not of great economic significance, except locally, in ordinary seasons.  During periods of extreme drought it may be of critical importance on grazing areas from the standpoint of the carrying capacity of the range.

(9) Kangaroo rats are easy to poison by following the same formula as that used by the Biological Survey for destroying prairie dogs.

(10) In many places unsuited to extensive grazing or agriculture spectabilis does no appreciable damage.  It is one of the most interesting of all the rodents peculiar to our Southwestern deserts, and should not be molested except where it is destructive.

BIBLIOGRAPHY.

ALLEN, J. A.

1895.  On a collection of mammals from Arizona and Mexico, made by Mr. W. W. Price, with field notes by the collector.  Bull.  Amer.  Mus.  Nat.  Hist., vol. 7, art. 6, pp. 193-258. 17 figs. in text.

BABCOCK, S. M.

1912.  Metabolic water:  Its production and role in vital phenomena.  Research Bull.  No. 22, Univ.  Wisconsin Agr.  Exp.  Station, pp. 159 and 170, March.

BAILEY, V.

1905.  Biological survey of Texas.  North Amer.  Fauna No. 25, Biol.  Surv., U. S. Dept.  Agr., pp. 222, 16 pls., 24 figs. in text.

CLEMENTS, F. E.

1905.  Research methods in ecology.  Lincoln, Univ.  Pub.  Co., pp. xvii, 334, 85 figs. in text.

GRIFFITHS, D.

1910.  A protected stock range in Arizona.  Bull.  No. 177, Bur.  Plant Ind., U. S. Dept.  Agr., pp. 28, 6 pls., 1 fig. in text.

GRINNELL, JOSEPH.

1921.  Revised list of the species in the genus Dipodomys.  Journal of Mammalogy, vol. 2, No. 2, pp. 94-97, May 2.

MCATEE, W. L.

1921.  Farm help from the birds.  In Yearbook of the U. S. Dept.  Agr. for 1920, pp. 253-270; unnumbered figs. in text.

MERRIAM, C. H.

1890.  Description of three new kangaroo rats, with remarks on the identity of Dipodomys ordii of Woodhouse.  In North Amer.  Fauna No. 4, Div.  Ornith. and Mamm. (Biol.  Surv.), U. S. Dept.  Agr., 41-49.

NELSON, E. W.

1918.  Smaller mammals of North America.  Nat.  Geog.  Mag., vol. 33, No. 5, pp. 371-493; numerous unnumbered figs. and colored pls. in text.

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