PAPERS ON BIOLOGY AND AGRICULTURE 157 



possibly five thousand Indians went up and down the Rock 

 River valley and had a few small villages along it. Hunting 

 and fishing, not agriculture, were the occupations, and con- 

 sequently these early people were roving instead of settled 

 in certain locations. This has had its influence on the vege- 

 tation, both in the way of less disturbance to it than would 

 result from a settled agricultural population and in the way 

 of the relation of the Indians to prairie fires. These were 

 pui-posely set for various reasons and have unquestionably 

 had an enormous influence on the native vegetation. The 

 exact extent of this influence may never be definitely known, 

 but the early records of the whites agree in furnishing di- 

 rect and indirect evidence of great weight as to the colossal 

 effect. Early records of Ogle County, besides prairie fires 

 of smaller size, mention two that occun'ed in successive years 

 and lan from the Mississippi River eastward to the Rock 

 River. 



When the whites began settlement about 1840 woodlands 

 extended along the Rock on either side for varying distances 

 and along its tributary streams. According to the earnest 

 accounts the prairie ran down to the water's edge in only 

 a few places. Elsewhere were the so-called "groves," patches 

 of woodland of varying size usually along water courses and 

 in the neighborhood of springs. These woodlands must not 

 be understood as mere narrow belts along the creeks; fre- 

 quently they occupied considerable areas. By far the larger 

 part of the county was undulating prairie land. Perhaps 

 15-20 per cent may be said to have been woods. It is in- 

 teresting to note that the early accounts of these "groves" 

 mention oaks, walnuts, elms, maples, hickory. This is a 

 rather different community from the prairie grove of the 

 present time. The same early accounts speak of the wood- 

 lands along the Rock and its tributaries as containing oaks, 

 walnut and butternut, hard maple, elm, hickory. Here the 

 assemblage is characteristic today. An account of the 

 woods west of the Rock, in Mount Morris township, written 

 about the middle of the nineteenth century, mentions them 

 as scrub timber growth in what was largely an open country. 

 The reason for the scrubby form is given as prairie fires. 



