454 BOTANICAL GAZETTE [june 



growth of plant life on the bottom only. The Thornton swamp 

 lies directly south of Chicago and between the Valparaiso moraine 

 and the Calumet beach line. The Furnessville swamp is east of 

 Mineral Springs, and at about the same distance from Lake 

 Michigan. Both of these swamps have reached the forest stage 

 of development, although there may be standing water in the 

 depressions in the early part of the season. The third swamp, that 

 at Wilhelm, is ecologically of a more advanced type. There is 

 little standing water at any time, and the trees (oak, beech, and 

 hard maple) indicate the approach of the climax forest. 



Nearly all of the other associations under consideration are 

 located on morainic drift, either within the region once occupied 

 by Lake Chicago or on the moraine forming the uplands about its 

 borders. Within the Chicago Lake area this till material has 

 been somewhat worked over by water action, but not to a degree 

 sufficient to entirely destroy its drift character. On the east bank 

 of the Des Plaines River, just below its junction with the Sag, is 

 the town of Lemont, Illinois. Here there is an outcrop of lime- 

 stone which forms several small rock ravines. An abandoned 

 stone quarry in the vicinity, as well as a stone wall at Palos Park 

 and a quarry at Thornton, offer very similar pioneer rock surface 

 habitats. East of Lemont near Palos Park on the edge of the 

 Valparaiso moraine is an upland oak forest which is probably a 

 subclimax forest. Excellent secondary successions in cut-over oak 

 forest, in various stages toward reforestation are found south of 

 Lemont near Joliet. East of Joliet along Hickory Creek near New 

 Lenox are much more mesophytic oak-hickory upland forests. 

 At other places we find climax forests of the beech-maple type. 

 At Smith, Indiana, a few miles east of the Wilhelm swamp forest, 

 and at Otis, Indiana, southeast of Chicago, are primeval wood- 

 lands containing beech and hard maple of very large size, placing 

 them without question in the climax area of the eastern United 

 States. Along the Des Plaines River south of the northern 

 boundary of Cook County, near Wheeling, Illinois, are mesophytic 

 forests on uplands in which the presence of Acer saccharum indicates 

 a greater degree of mesophytism than is frequently met with so 

 far west in northern Illinois. No Fagus grand if olia has been 



