0398.

Thirty-seven skulls from the collection of the Museum of Natural
History of The University of Kansas and two skulls from the United
States National Museum were measured. The measurements are on file in
the Library of The University of Kansas in a dissertation deposited
there by me in 1963 in partial fulfillment of requirements for the
degree of Master of Arts in Zoology. Specimens used were: White-winged
Doves, KU 19141, 19142, 19143, 19144, 19145, 19146, 19147, 23138,
23139, 24337, 24339, 24341, 23592, 23593, 24340, 31025, 31276; Mourning
Doves, KU 14018, 14781, 15347, 15533, 15547, 15550, 15662, 15778,
15872, 16466, 17782, 17786, 17788, 17795, 19153, 19242, 20321, 21669,
22394, 22715; Eared Doves (_Zenaidura auriculata_), USNM 227496,
318381. Additionally, the skulls of the Zenaida Doves mentioned above
were measured. All measurements were made with a dial caliper and read
to tenths of a millimeter.

ACKNOWLEDGMENTS

My appreciation is extended to Professor Richard F. Johnston, who
advised me during the course of this study, and to Professors A. Byron
Leonard and Theodore H. Eaton for critically reading the manuscript.

I would like also to acknowledge the assistance of Dr. Robert M. Mengel
and Mr. Jon C. Barlow for suggestions on procedure, and Mr. William C.
Stanley, who contributed specimens of Mourning Doves for study. Mr.
Thomas H. Swearingen offered considerable advice on production of
drawings and Professor E. Raymond Hall suggested the proper layout of
the same and gave editorial assistance otherwise, as also did Professor
Johnston.

MYOLOGY

The jaw musculature of doves is not an imposing system. The eating
habits impose no considerable stress on the muscles; the mandibles are
not used for crushing seeds, spearing, drilling, gaping, or probing as
are the mandibles of many other kinds of birds. Doves use their
mandibles to procure loose seeds and grains, which constitute the major
part of their diet (Leopold, 1943; Kiel and Harris, 1956: 377; Knappen,
1938; Jackson, 1941), and to gather twigs for construction of nests.
Both activities require but limited gripping action of mandibles. The
crushing habit of a bird such as the Hawfinch (_Coccothraustes
coccothraustes_), on the other hand, involves extremely powerful
gripping (see, for example, Sims, 1955); the contrast is apparent in
the development of the jaw musculature in the two types. Consequently,
it is not surprising to find a relatively