SwANTONl INDIANS OF THE SOUTHEASTERN UNlITED STATES 5 



Mississippi Alluvial Plain, the Mississippi "flood plain and delta"; 

 and (6) the West Gulf Coastal Plain, a "young grading inland to 

 mature coastal plain." The first of these extends along the coast 

 from Cape Cod to Cape Lookout; the second, from the latter point 

 to St. Johns Kiver; the third includes Florida south of St. Johns 

 River and Apalachee Bay; the fourth and sixth embrace the entire 

 coastal plain north of the Gulf of Mexico and are separated merely 

 by the fifth area, the alluvial flood plain of the Mississippi. The 

 Nashville Basin, a limestone island in the Interior Low Plateaus is 

 also of ethnological significance, and the Lexington Plain, or "blue 

 grass country," may have been of equal importance in prehistoric 

 times, but the information that has come down to us from the tribes 

 last in occupancy does not indicate it. 



Geographically, the Southeast is one of the newest as well as one of 

 the richest parts of North America. 



It is in the warmest section of the north temperate zone, the de- 

 crease in temperature from south to north, or rather southeast to 

 northwest, being fairly uniform except along the Appalachian 

 Mountains, the highest land-masses east of the Rockies, which intro- 

 duce a disturbing element. Throughout most of the region the av- 

 erage temperature during July is 80° or more, and over the rest of 

 it not lower than 75° except in the Appalachians where it descends 

 below 70°. The average annual maximum temperature is between 

 90° and 100°, somewhat exceeding the latter figure along the margin 

 of the Western Plains. In January the difference between the 

 southern and northern sections varies more widely, a small portion 

 near the tip of Florida maintaining 65° or more, north of which we 

 find successive belts of lower and lower temperatures down to 35°, 

 and even below 30° in the high West Virginia mountains. The 

 minimum at the tip of Florida is in the neighborhood of 40° and 

 along the northernmost fringe somewhat under zero. (See maps 4 

 and 5.) 



The greater part of the Southeast is in the zone where south- 

 westerly winds prevail, but Florida and parts of the Gulf coast fall 

 under the influence of the easterly trades, particularly in summer, 

 and, in spite of the fact that the northern part is in the lee of the 

 Rocky Mountains, the two work together to provide an abundant 

 rainfall almost everywhere, the only handicap being the West India 

 cyclones, which often come along with the trades in spring and 

 autumn to be hurled upon the southern coast. An annual average 

 rainfall of between 40 and 60 inches is registered everywhere and 

 more than 60 inches in a few spots on the coast and in the Appala- 

 chians, one section of the latter even exceeding 80. In January 

 there is less proportional precipitation on the Atlantic Coast than in 



