THK BLUE-GRASSES 95 



The distribution of blue-grass south of the glacial 

 drift is exceedingly interesting. In this region it is 

 confined to the magnesian limestone soils of the geo- 

 logical area known as the Cambrian. A great tongue 

 of this limestone soil extends southward from Cincin- 

 nati, Ohio, into northern Kentucky, a distance of 

 about one hundred and ten miles, and is nearly one 

 hundred miles broad. This constitutes the famous 

 ' ' Blue-Grass Region ' ' of Kentucky. The geographical 

 centre of this region is a point about twenty-two miles 

 north of the City of Lexington, and it extends about 

 twenty-five miles south of that city. It is in this re- 

 gion that most of the blue-grass seed of the country is 

 harvested. From this a narrow strip extends into 

 Tennessee, and there spreads out and occupies the 

 ' ' central basin ' ' of that State. Blue-grass again ap- 

 pears in the mountain valleys of eastern Tennessee and 

 western Virginia, where it is an important pasture- 

 grass. It appears more sparingly in the hill country 

 of the western Carolinas, northern Georgia, and north- 

 ern Alabama. Some blue-grass is also grown on the 

 black, sticky prairie soils of northeastern Mississippi. 

 The Cambrian soils above referred to are the only 

 southern soils that at all resemble those of the region 

 north of the Ohio River, and it is only on them that the 

 t} pe of farming prevalent in the North is found in the 

 South. Aside from the exceptions just noted, blue- 

 grass is confined rather stridlly to the glacial drift of 

 the Northern States. Its very general distribution 

 over the drift area is supposed to be due to the lime, 

 magnesia, and, perhaps, potash in these soils. Climatic 

 conditions are also more favorable to blue-grass in the 



