62 



Viola hlanda Viola rotundifolia 



Viola puhescens 



As will be readily seen from the list, this formation is more 

 complex and varied than all the others. Forest, meadow, 

 swamp, spring and pasture formations have played a role, to a 

 greater or less extent, in establishing a gulf and valley formation 

 that is characteristic of the plateau-region of the state of New 

 York at an average elevation of 1,700 feet above sea-level. 



5. Plateau-Pasture Formation 



This is the only formation that has been established through 

 the lumbering activity of man, and the more or less complete 

 destruction of the typical forest-flora tends to introduce condi- 

 tions that would favor a rather complex succession which, if left 

 to itself, would finally reestablish the original conditions. But 

 the succession is checked at present by the cattle feeding upon it, 

 and the formation retained in a mixed xero-mesophytic condition, 

 while the presence of several more or less extensive swamps aid in 

 the establishment of at least a partial horizontal zonation, in which 

 hydrophytic forms become gradually replaced by mesophytic ones 

 and these in turn yield to more or less xerophytic species, especially 

 where a plateau-swamp is adjacent to a crest. 



The plants found are as follows: 



Achillea Millefolium Panicum capillare 



Acer Saccharum Panicum sanguinale 



Alnus viridis Poa annua 



Bellis perennis Ranunculus pennsylvanicus 



Brunella vulgaris Sisyrinchium bermudianum 



Campanula americana Gyrostachys cernua 



Fragaria virginiana Ulmus americana 



Hieracium pilosella Verbena bracteosa 



Lycopodium complanatum Viola obligua 

 Lycopodium obscurum var. den- 

 droideum 



The subjoined map, comprising part of the area discussed, 

 namely the greater part of the drainage basin of Amster Brook, 

 will serve to illustrate some of the facts brought out in this paper. 



