152 T O R R E Y A 



. 1909. The Coleoptera of Isle Roj^ale, Lake Superior, and their relation to the North 



American centers of dispersal. Ecol. Surv. Isle Royale. Mich. Geol. Rept. 1908: 157- 

 215. 

 . 1915. The variations and ecological distribution of the snails of the genus lo. Mem. 



Nat. Acad. Sci. 12 (2) : 1-86. 

 Allen, J. A. 1892. Variations in vertebrated animals. Amer. Nat. 26 : 87-89. 



. 1905. The evolution of species through climatic conditions. Sci. 22: 661-668. 



Anderson, E. 1937. Cytologj- in its relation to taxonomy. Bot. Rev. 3: 335-350. 



AND K. Sax. 1936. A cytological monograph of the American species of Tradcs- 



caiitia. Bot. Gaz. 97: 433-476. 

 AND L. HuBRiCHT. 1938. Hybridization in Tradcscantia. III. The evidence for in- 



trogressive hybridization. Amer. Jour. Bot. 25: 396-402. 

 AND R. E. Woodson. 1935. The species of Tradcscantia indigenous to the United 



States. Arnold Arboretum Contrib. 9: 1-132. 

 AxELROD, D. I. 1941. The concept of ecospecies in Tertiary paleobotany. Proc. Nat. Acad. 



Sci. 27: 545-551. 

 Babcock, E. B. AND D. R. Cameron. 1934. Chromosomes and phylogeny in Crcpxs. II. 



Univ. Calif. Pub., Agr. Sci. 6: 287-324. 

 AND G. L. Stebbins, Jr. 1937. The genus Youngia. Carnegie Inst. Wash. Publ. 



484: 1-106. 



AND . 1938. The American species of Crepis, their interrelationships and dis- 



tributed as affected by polyploidy and apomixis. Carnegie Inst. Wash. Publ. 504: 1-199. 

 Baldwin, J. T., Jr. 1941. Galax: The genus and its chromosomes. Jour. Hered. 32: 249- 



254. 

 Benson, L. 1941. The mesquites and screw-beans of the United States. Amer. Jour. Bot. 



28: 748-754. 

 Braun, E. L. 1937a. Some relationships of the flora of the Cumberland Plateau and the 



Cumberland Mountains in Kentucky. Rhodora 39: 193-208. 

 . 1937b. A remarkable colony of coastal plain plants on the Cumberland Plateau 



in Laurel County, Kentucky. Amer. Midi. Nat. 18: 363-366. 

 Camp, W. H. 1941. Studies in the Ericales : A review of the North American Gaylussa- 



cieae; with remarks on the origin and migration of the group. Bull. Torrey Club 68: 



531-551. 



. 1942. On the structure of populations in the genus Vaccinium. Brittonia 4: 189-204. 



CocKERELL, T. D. A. 1906. The evolution of species through climatic conditions. Sci. 23 : 



145-146. 

 Du RiETZ, G. E. 1930. The fundamental units of biological taxonomy. Svensk Bot. Tidskr. 



24: 333-428. 

 Fassett, N. C. 1941. Mass collections : Ruhus odoratus and R. parviflorus. Ann. Mo. Bot. 



Garden 38: 299-367. 

 Fernald, M. L. 1926. The antiquity and dispersal of vascular plants. Quart. Rev. Biol. 



1: 212-245. 

 . 1931. Specific segregations and identities in some floras of eastern North America 



and the Old World. Rhodora 33: 25-63. 

 Gattinger, a. 1901. The Flora of Tennessee. Nashville. 

 Gleason, H. a. 1923. The vegetational history of the Middle West. Ann. Assoc. Amer. 



Geogr. 12: 39-85. 



. 1925. Species and area. Ecology 16: 66-74. 



G<x>d, R. D'O. 1931. A theory of plant geography. New Phytol. 30: 149-171. 



