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country. The most nearly continuous and undisturbed areas of woodland 

 are those which clothe the tops and sides of the bluffs which, as already 

 mentioned, form the outer margins of the river-bottoms. These are ex- 

 clusively hardwood formations, the dominant tree at higher levels being 

 the white oak (Quercm alba), with which are commonly associated the 

 sugar maple (Acer saccharum) , pig-nut hickory (Hichoria glabra), red 

 oak (Qnercus rubra), shell-bark hickory (Hichoria ovata), bass-wood 

 (Tilia americana), elm (Ulmus sp. not det.), beech (Fagus ferruginea) , 

 dogwood (Comus florida) and aspen (Populus tremuloides). Where- 

 ever these woodlands are sufficiently open to admit sunlight blue 

 grass usually springs up and forms a continuous cover to the ground or, 

 if the soil is exceptionally dry, an aggregation of more or less scattered 

 tufts with interspaces of bare earth. Where the grass is thick one 

 usually finds Melanoplus scudderi, while in places where it is short and 

 scattered Spharagemou bolli and Melanoplus luridus are usually en- 

 countered. Along the edges of the woods in undisturbed ground these more 

 strictly sylvan types were observed to meet and to intermingle with a 

 campestral assemblage which usually included Syrbitla admirabilis, Arphia 

 xanthoplera, Chortophaga viridifasciata and Encoptolophus sordidus. In 

 scrubby areas and in tall herbaceous growths Atlanticus testaceus was 

 fairly common. 



In strong contrast to the foregoing group is an assemblage character- 

 istics of moist areas. Such areas most frequently occur at the outer 

 margin of the river bottoms where the seepage from the neighboring bluffs 

 keeps the ground perpetually moist and soggy. The soil in such places is 

 a typical muck, frequently intermixed with gravel and silt. In nearly all 

 the swamps I have visited the vegetable content of the soil appeared 

 to be thoroughly decomposed. At one place (1) in a wet depression in 

 the midst of a fairly large woods on the upland about one and a half 

 miles northwest of West Lafayette the substratum was a true peat. In 

 the bottomland swamps, however, the soil appears in all cases where I 

 have examined it to be a muck. Such a swamp harbors a rich vegetation 

 of which the dominant member in wetter spots is rice cutgrass (Homalo- 

 cenchrus oryzoides) with which are often associated cat-tails (T.uplia lati- 

 folia) and jewel-weeds (Impatiens bipora). Surrounding the cutgrass 

 areas in slightly dryer ground is usually a dense thicket composed of tall 

 herbaceous plants, especially composites, among which I noted the taller 

 ragweed (Ambrosia trifida), ironweed (Ycrnonia fasciculata) , joepye- 



