78 THE PLANT SPECIES 



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Blair, A. P. 1955. Distribution, variation, and hybridization in a relict 

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Blair, W. F. 1951. Interbreeding of natural populations of vertebrates. 

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Burma, B. H. 1954. Beality, existence, and classification: a discussion 

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Burton, G. W. 1951. Quantitative inheritance in pearl millet (Pennise- 

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Camp, W. H. 1951. Biosystematy. Brittonia, 7, 113-27. 



Camp, W. H., and C. L. Gilly. 1943. The structure and origin of spe- 

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Castle, W. E. 1954. Coat color inheritance in horses and in other mam- 

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Clausen, J. 1951. Stages in the Evolution of Plant Species. Cornell 

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Cockrum, E. L. 1952. A check-list and bibliography of hybrid birds in 

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Danser, B. H. 1929. Uber die Begriffe Komparium, Kommiskuum und 

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Darlington, C. D. 1940. Taxonomic species and genetic systems. In The 

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Davidson, J. F. 1954. A dephlogisticated species concept. Madrono, 

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Dobzhansky, T. 1935. A critique of the species concept in biology. 

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Dobzhansky, T. 1951. Genetics and the Origin oj Species. 3rd ed. Co- 

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Dobzhansky, T. 1953. Natural hybrids of two species of Arctostaphylos 

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Dobzhansky, T., and C. Epling. 1944. Contributions to the genetics, 

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l)u Rietz, G. E. 1930. The fundamental units of biological taxonomy. 

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Fisher, II. A. 1954. Retrospect of the criticisms of the theory of natural 



