94 BOTANICAL GAZETTE [auoust 
two, the waxberry and the Hudsonia, are characteristic of just this 
situation, in and to which they have apparently been adaptively 
developed. Towards the inner dune beaches another low shrub 
comes in on the slopes, though dwarfed and not abundant, the 
common blueberry, Vaccinium pennsylvanicum; it is evidently 
not here at home, but its somewhat xerophytic habit permits it to 
exist. As these various plants grow older and extend their patches, 
they run together more or less, sometimes two, sometimes three, 
and even all four. Later others are added to them, initiating the 
juniper mats and the woods carpet, later to be considered. 
The contrast between the vegetation of the outer and the shel- 
tered slopes of the dune beaches comes out with striking clearness 
a few hundred yards north of Eel Brook, where it happens the entire 
plain is very narrow, and slopes in both directions from a central 
higher crest. Outside of this can be seen only the beach grass and 
its accompanying forms as listed above, while inside the various 
xerophytic shrubs show to great perfection. 
THE SWALES. 
Between the cpen grass plain and the woods occurs a transition 
zene marked not only by an intermediate vegetation but also by 
distinctive physical features as well. First of all it is characterized 
by the presence of several great turf-carpeted and tree-bordered 
swales, morpholcgically hollows between the dune beaches which 
here spread much farther apart than usual. They are well show? 
in figs. 8, 10, 11. They are best developed in the widest part of the 
plain, hardly cccurring towards its southern or northern ends, and 
outside cf them runs a line of higher dune beaches, which indeed 
can be traced through most or all the length of the plain (jig. 2). 
The swales are narrow southward, but broaden northward, deepening 
as they go, until in some cases they dip beneath the water-table 
(thus exhibiting pools), after which they rapidly narrow and ms¢ 
to disappear northward. Again, the trees of this zone, occurring 
always along the slopes of the dune beaches, do not exhibit a trans’ 
tion of size and age to those of the sandy woods, but are alway> 
so much smaller and younger as to be sharply marked off from them, 
the case shown in fig. ro being very exceptional, and that of 7+ 8 
