~ 
20 Tue Witson Burretin, No. 74. 
herbaceous growth is largely more or less xerofytic in natur. 
Many of these black oak woods are giving place to a more 
mesofytic type of woods, to which the term “mixt forest” has 
been applied by Gleason.1. The succession is evidenced by the 
inroad of hickories and vines, which giv proof of a more 
mesofytic soil, altho the tree growth may still retain about the 
same percentage composition as befor. This is because con- 
ditions are ripe for succession, but supercedance of the domi- 
nant species takes place after the death of the dominant spe- 
cies of the first association. This is taking place slowly, giv- 
ing expression to a woods in which the trees are still largely 
typical of the black oak woods, while the undergrowth is dis- 
tinctly of the mixt forest type. 
Mrxt Forest. The forest association to which this term 
has been applied is well developt, especially on some of the 
ridges near the Illinois River. It is a forest of five or six 
principal kinds of trees, of which as high as 50% may be 
black oak (Quercus velutina). Aside from this tree the prin- 
cipal trees are hickories (Hicoria cordiformis and Hicoria gla- 
bra villosa), hackberry (Celtis occidentalis), elms (Ulmus 
americana and fulva, bur oak (Quercus macrocarpa) and 
white oak (Quercus alba). The ground supports a luxuriant 
growth of vines, herbs and shrubs. The vines, Virginia 
creeper, bittersweet, poison ivy, and grape are very character- 
istic of the earlier stages of this association. Later the ground 
is coverd with more typical mesofytic plants. 
Both of these two types of upland woods are characterized 
by quite a number of birds, which are not so exclusivly in- 
sectivorous as those of the bottomland woods. Several of 
these are far more often heard than seen and but very few of 
the species are obtrusiv. There is comparativly little differ- 
ence in the species list of each of these two associations as 
nearly every bird that occurs in one occurs in the other also. 
"Gleason, H. A. The Vegetation of the Inland Sand Deposits of 
Illinois, Bulletin, Illinois State Laboratory of Natural History, 
9:135, 1910. 
