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JOURNAL OF MAMMALOGY 
BIBLIOGRAPHY 
Castle, W. E. 1920. Genetics and Eugenics. Harvard University Press, 
Cambridge, Mass. 
Morgan, T. H., Sturtevant, A. H., Muller, H. J., and Bridges, C. B. 1915. 
The Mechanism of Mendelian Heredity. Henry Holt and Co., New 
York. 
Morgan, T. H. 1919. The Physical Basis of Heredity. J. B. Lippincott Co., 
Philadelphia and London. 
Wright, S. 1917. Color Inheritance in Mammals. Journal of Heredity, vol. 
8. nos. 5-9. 
Agricultural Experiment Station, Storrs, Connecticut. 
. A HYBRID DEER OF THE Fa GENERATION 
By Hartley H. T. Jackson 
[Plate 8] 
INTRODUCTION 
Among deer hunters who search for their spoils on the eastern slopes 
of the Cascade Mountains in the state of Washington, it is quite gener- 
ally known that in a certain region the mule deer {Odocoileus hemionus 
hemionus) and the Columbian black-tailed deer {Odocoileus columhianus 
columhianus) hybridize. This area is where the western range of 
of the mule deer and the eastern range of the black-tail overlap. It 
may be roughly outlined by the summit of the Cascade Mountains 
on the west; the region of Stampede (or Yakima) Pass and lakes Keeches 
and Keechelus on the north; a line drawn north and south through a 
point 6 miles east of Signal Peak, the Tieton Basin, and Frost Mountain 
on the east; and Mount Adams on the south. Mr. James Henderson 
writes: 
This cross breeding of the mule deer and the Columbia black-tailed deer is not 
common The different varieties of deer have their respective ranges 
very well defined, the mdle deer seldom going to the summit of the divide and 
never, to my knowledge, beyond on the west slope. They are very much more 
scarce than the black-tails near the summit. I believe the lack of mates of their 
own kind leads the bucks of this variety to cross with the does of the black-tailed 
kind. Their offspring will then mate with either. (Letter to the U. S. Biological 
Survey from James Henderson, Mabton, Washington, April 24, 1917.) 
