INTRODUCTION. 
In the Autumn of 1899, the writer began the 
ecological study of Big Spring Prairie, situated in 
Wyandot, Seneca, and Hancock counties, Ohio. This 
prairie is about ten miles long, and from one half to a 
mile wide. From its shape, it might aptly have been 
termed Horse-shoe Prairie. It orginates just north of 
Carey, in fact a portion of it les within the corporate 
limits of the town; thence it extends four miles in a 
northwesterly direction; here, making a sweeping curve, 
it extends three miles westward; again widely curving, 
it extends three miles in a southwesterly direction, 
ending about one-half mile north of Vanlue, Hancock 
county. About two and one half miles of prairie lie in 
Wyandot county, about the same extent in Seneca 
county, and five miles in Hancock county. The widest 
portion occurs in Seneca county, where it curves to the 
westward, the next widest in Hancock county, where 
it curves to the southwest. 
The term prairie has been applied to the more or 
less grassy plains of the treeless regions both east and 
west of the Mississippi River. The eastern prairies 
differ in many particulars besides size, from those in 
the extreme west near the foot of the Rockies. Between 
these limits, we may find all gradations in specific 
characteristics. The typical eastern prairies are prop- 
erly natural meadows; some, in fact, border on thé 
semi-marsh type. ‘This belt comprises the region from 
the eastern prairie limit to Missouri and Iowa. West 
of this there is a gradual gradation through the steppe 
type to the semi-desert near the Rockies. 
The most striking differences between the eastern 
and western. prairies are the climatic factors of rainfall 
and general humidity of the atmosphere. 
