Il6 ADAMS. 



north, a northward migration of life took place. I have hoped 

 that the Postglacial centers of dispersal could be more definitely 

 located than simply in the South, and I have found from a study 

 of geographical relationship of the fauna and flora that one im- 

 portant center has been in Southeastern United States, with Chat- 

 tanooga as the approximate center. 



GEOGRAPHICAL AFFINITIES OF THE TEMPERATE FAUNA AND 

 FLORA OF EASTERN UNITED STATES. 



Several years ago my attention was first attracted toward the 

 Southeast in attempting to get some idea as to the probable 

 geographic origin of our Illinois reptilian and amphibian fauna. 

 I was then led to conclude that this fauna was primarily of 

 southeastern origin. At the same time I learned that the flora of 

 the upper Mississippi valley came from the Southeast. MacMillan 

 ('92, p. 653) said of the Minnesota valley, with respect to its 

 higher seed plants : " While continentally central, it is by no 

 means botanically central, but is peculiarly an Atlantic coast and 

 southern region." With regard to the species he says (ibid., 

 p. 717): " As a whole the metaspermatic flora of the Minnesota 

 valley presents itself as distinctly eastern and southern by species 

 as before by genera." Dr. Bessey ('92 and 'oo) has shown 

 that the trees and shrubs of Nebraska came from the Southeast. 

 He says : "A close study of the foregoing facts as to the dis- 

 tribution of our woody plants shows that nearly all have probably 

 migrated to the plains from the east. . . . Nearly all our trees 

 have come up the Missouri bottoms and spread from the south- 

 eastern corner of the state west and northwest." The trees of 

 Kansas clearly show the same origin, as is easily seen by com- 

 paring Mason's ('92) list of Kansas trees with the one given by 

 Dr. Bessey. 



Cope ('96, p. 895) has pointed out the Eastern origin, or 

 center of distribution, of our fish, amphibian, and turtle fauna. 

 Upon closer analysis this fauna will undoubtedly indicate a 

 southeastern origin. I have not been able to learn that students 

 of birds and mammals have especially noticed that Southeastern 



1 By reference to a good contour map of the Mississippi valley, it will be easy to 

 see the highway by which this flora reached this region from the Southeast. 



