56 



areas that are partly uneven and hilly, and partly level. We 

 find the formations resulting from these physical factors estab- 

 lished somewhat as follows: 



1. Plateau-Forest Formation. 



2. Plateau-Meadow Formation. 



3. Plateau-Swamp Formation. 



4. Plateau-Gulf-and -Valley Formation. 



5. Plateau-Pasture Formation. 



While the conditions that developed or at least helped to 

 develop the first four of these formations have been brought about 

 by nature as transitional and final forms of vegetation, the fifth 

 formation, or plateau-pasture formation, has been developed 

 through the activity of man. An enumeration of the different 

 species that constitute the various formations, specially those 

 which make up the facies of each formation, will tend to show 

 which plant-forms are more or less significant for each of the 

 different formations, and which are to be considered as invaders, 

 or rather as common for all or most of them. 



I. Plateau-Forest Formation 



The forest, so far as it occupies the region north of the water- 

 shed of Mohawk Hill, at an average elevation of 1,700 feet above 

 sea-level and in horizontal extension between latitude 43° 30' 

 and 44° north, is a mixed formation. It is a mixture of the typical 

 deciduous-leaved and needle-leaved forest-formations, and is 

 passing, at present, from the closed into the open stage, and from 

 that of primary to that of secondary growth. 



The predominant character of its flora is mesophytic, although 

 more or less hydrophytic forms may occasionally occur wherever 

 members of the swamp or spring formation have invaded the 

 forest, as is very often the case. 



Amqng trees the more characteristic ones are the following: 



Abies alba Hicoria minima 



Abies balsamea ' Juglans cineria 

 Acer Saccharum Larix laricina 



Acer rubrum Negundo acer aides 



Fagus grandifolia Picea Mariana 



