122 ILLINOIS ACADEMY OF SCIENCE. 



it everywhere gives character to the woodland. The list of trees 

 occurring in it with sufficient frequency to be considered a part 

 of the general formation includes the following: Quercus velu- 

 tina, Q. coccinea, Q. alba, Q. macrocarpa, Q. rubra, Q. Muhlen- 

 bergii, Carya ovata, Prunus serotina. If one may venture an 

 opinion from the fragmentary data now available, the following 

 would appear to be the original distribution of the species men- 

 tioned. 



(a) A group of relatively xerophytic species occupied the 

 rapidly eroding lands and formed a zone of considerable width 

 on the prairie side of all forested areas. The Black and Burr 

 Oaks and the Shellbark Hickory are most prominent. Wherever 

 the original line of contact between the prairie and the forest can 

 yet be found, the Burr Oaks make up the outer fringe, and where 

 cutting has exposed the Black Oaks to the sweep of drying 

 westerly winds they are usually dying. 



(b) A more mesaphytic group (Q. alba, 0. rubra, P. serotina) 

 occupied most of the forested region not yet deeply eroded, show- 

 ing a tendency to occur also in the more protected central part 

 of large forests, the margins of which were occupied by Black 

 and Burr Oaks. 



2. Maple Association. 



So far as the present conditions of the timberland show, the 

 maple formation is restricted to an area of less than a square 

 mile near the head of Mud Creek and a similar area reported 

 from Kyte River. The latter I have not been able to visit. It 

 will be recalled that, according to Leverett, the valleys of both 

 streams are preglacial, and in this particular the situation differs 

 from that of most other forest areas in the county. 



This association is doubtless to be correlated with the Beech- 

 Maple formation of other localities. The most plentiful species 

 are Acer sacharum, Ulmtis americana, and Fraximis americana. 

 Ostrya virginiana is almost as common as the preceding, and 

 there are many large trees of Quercus alba and Q. rubra. Tilia 

 americana, both species of Juglans and a few specimens of Prunus 

 serotina make up the remainder of the forest. Beech is of course 

 wholly absent. Abundant seedlings of basswood, elm, ash, Ostrya 

 and maple promise a continuation of the same type of forest if 

 properly protected. The oaks and the wild cherry, mostly mature 

 trees, are doubtless to be interpreted as relics of a former condi- 

 tion not yet wholly past. 



