﻿44 BOTANICAL GAZETTE [January 



channels the areas occupied by the different societies are so 

 limited that any satisfactory representation of them on the scale 

 of the present map was deemed impossible. Therefore they 

 are left unshaded. Also the lowland societies along the margins 

 of smaller streams and lakes and in swamps among the hills are 

 omitted entirely from the map. The reason for this is in part 

 the same as the one given for the larger channels, and also in 

 part this, that although some of the swamps are large enough to 

 map well on the present scale, yet to trace their margins 

 accurately would require more time than it would be worth, 

 and to map them inaccurately would not be true to the instinct 

 of the work. 



Steep slopes where erosion is at present rapid, as along the 

 margins of the many stream valleys and along old glacial chan- 

 nels, are occupied by societies III, IV, and V. The character 

 of the soil seems to make no difference here, the drainage being 

 quite complete and the accumulation of humus impossible. It 

 has also been found impracticable to indicate these very narrow 

 areas upon the map. 



In the southern tier of townships, all the heavy clay soil, 

 whether it be rolling moraine or level till plain, was originally 

 occupied by the beech-maple society (I). In the lighter loamy 

 spils are usually found the oak-hickory society (III), with tran- 

 sition zones between it and I held by the maple-elm-agriniony 

 society (II). The very sandy loam bordering the deep narrow 

 valley of the Thornapple River, and spreading eastward from 

 Alaska and Labarge nearly to the Elmdale till plain, is occupied 

 by the oak-hazel and the oak-pine-sassafras societies (IV and V). 

 This loam is in many places as sandy as the soil of the Grand 

 River sand plain ; it might almost have been denoted as sand. 



Within the "big bend" of the Grand River is an area of 

 decidedly clayey country occupied by the oak-pine-sassafras 



(V) 



It 



» 



appears as though this area were well on the way toward society 

 IV at the time of clearing. But the marked presence of sassa- 

 fras, wormwood, sand bur, Solidago ne?noralis, and other forms of 

 society V, makes it impossible to classify it elsewhere. 



