64 VICTOR E. SHELFORD. 



made up of blueberry, choke cherry and New Jersey tea. The 

 oaks (Quercus velutina) constitute a much thicker stand than 

 the pines but the type which we are considering here has the 

 open places grassy and covered with a growth of vetch (Tephro- 

 sia virginiana), golden-rod and other Composite. The chief 

 points of study were ^A, at Miller, Ind., 3.8, near Clark, Ind., 

 and 3C, at Dune Park. 



4. Red Oak Stage. 



This was originally the most abundant type of forest near 

 Chicago but areas which have not been disturbed by man are 

 few in number. On the sand, hickories are rare. The forest 

 is usually made up of black oak, red oak, and white oak. This 

 is true at 4^4, 46", and q.D, of the map. The more mesophytic 

 type is made up of white oak, red oak, and hickory, with the 

 red oak and the hickory dominating. Our type four then, 

 represents a range of conditions. All the stages are included 

 here and all are characterized by the absence of bare sand and 

 other mineral soil, and by the presence of a carpet of leaves 

 and humus w r hich covers the ground. There is a well marked 

 shrubby and herbaceous growth. The characteristic shrubby 

 species, are blueberry, Viburnum, Cormis, and Crataegus. The 

 shrubs are usually quite numerous and make thick stands 

 locally in the forest. The places studied are, 4^4, at Hessville, 

 Ind., 4C, at Liverpool, Ind. and 4!), at Beverly Hills in Chicago. 

 These represent white oak, red oak, and black oak on sand. 

 ^E, ^F and ^G, represent areas on till clay which are in some- 

 thing like primeval conditions. 



5. Beech Stage. 



This type is characterized by beech and sugar maple. The 

 mineral soil is covered with several centimeters of humus and 

 a very thick layer of leaves which is often matted together by 

 fungus hyphse. The number of species of trees is smaller but 

 the number of species of small shrubs is greater than in 

 the preceding stage. The number of individual shrubs how- 

 ever is smaller. Here the trees close the over-head spaces and 

 make a dense shade, while the lower forest is open. The locali- 



