448 



THE AMERICAN NATURALIST 



[Vol. LY 



10. On account of the frequency of dominant and pro- 

 gressive mutations and notwithstanding the difficulties 

 of seed germination this genus merits the attention of 

 geneticists. 



LITERATUEE CITED 



1. Bateson, W. Mendel's Principles of Heredity. Cambridge, 1909. 



2. Bateson, W. Problems of Genetics. New Haven, 1913. 



3. Duerden, J. E. Parallel Mutations in the Ostrich. Science, N. S., 52: 



165-168. 1920. 



4. Greene, E. L. Two New Lupines. Leaflets of Botanical Observation 



and Criticism, 2: 67-68. 1910. 



5. Heller, A. A. The North American Lupines— V. Muhlenbergia 7: 



85-95. 1911. 



6. Jeffrey, E. C. Spore Conditions in Hybrids and the Mutation Hj-poth- 



esis of de Vriea. Bo^. Gn^-.. 58 : 322-336. Pis. 22-25. 1914. 



7. Jepson, W. L. Flora of Middle Western California. San Francisco, 



1911. 



8. Martin, J. N., and H. S. Coe. Sweet Clover Seed. V. S. D. A. BuU. 



844, 1920. 



9. Morgan, T. H. The Physical Basis of Heredity. Philadelphia, 1919. 



Group. Muhlenbergia 6: 135-137. 1911. ^ 



11. Sturtevant, A. H. A Parallel Mutation in Drosophila funebris. 



12. de Vries, Hugo. ' The Mutation Theory. Chicago, 1909. 



