An associational study of Illinois sand prairie . Figure 1. Map of the region studied, the sandy ridp-es orislands showinr. as dotted areas, and the sandyloam flats or ancient stream channels showingas v/hite areas between. The ditches in themiddle, when compared with the abundant streamsof the uplands, give an idea of surface drainagein sand.

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Keywords: ., bookcentury1900, bookdecade1910, bookidassocia, booksubjecttheses