Development of the Vegetation of New York State 141 
districts where bare fissured rock or a covering of coarse rock 
fragments and worn boulders formed the terrain upon which 
vegetation development carried out its course and where, in 
many instances, it has been thrown back to the initial or early 
stages again as a result of destructive lumbering and fires — 
in some cases also by farming methods. It will be recognized 
that the problem for vegetation was originally and is now 
simplified by the fissured, fractured and greatly roughened 
surface and consequent moisture seepage and the filling of 
fissures and pockets by the finer products of weathering. 
Naturally an isolated, rounded summit of exposed rock, es- 
pecially where this is polished smooth, will always remain in 
the xerophytie or dwarf shrub and dwarfed and gnarled tree 
stage. 
2. The Development of Vegetation Upon Sand. 
Our interest in this connection centers in sand deposits 
which are compact and relatively stable. There is relatively 
little territory in New York where sand hes loose in dune 
formations subject to rapid shifting by wind action. There 
are however such eases on the shores of Lake Ontario and 
on Long Island notably at Montauk Point. In the former 
ease, sand dunes are occupied by chestnut, oak, white pine, 
bracken fern, ete. The course of development would, how- 
ever, carry us back to the early stage when the surface of the 
sand may have been temporarily held in place by algae and 
moss protonemata, while sand binding grasses and other sand 
binding plants and, later, shrubs gained a foothold and by 
the vigor of rhizome and root development bound the sand in 
place while the rapid vegetative multiplication spread a 
vegetation mat over the dune. Such in fact is essentially 
the course on sand beds in the Adirondacks, for example, 
although bracken fern rather than grasses, and the dwarf 
blueberry (Vaccinium angustifoltum Ait.) and Canada blue- 
berry (Vaccinium canadense Kalm) are the chief working 
units of vegetation in this early stage. 
The noteworthy areas of sandy soils in New York comprise 
first, sand deltas composed of flat deposits put down under 
