410 Part IV. Chapter 2, 
for example, are usually open while those on Wildwood beach are closed and 
have culminated in the forest type of vegetation. This argues for a greater 
age of the strand flora of Wildwood, as compared with that, for example, at 
Sea Side Park in the north. This conclusion is substantiated by the fact that 
the bays behind the sandy sea islands are converted into salt marshes in the 
south, while in the north they are wide and open bays of brackish or salt 
water. Physiographically and botanically the coast line from Bay Head south 
to Ocean City is younger than the coast south of the latter place extending 
to Cape May. 
Beach Formation. The beach formation exists at the several places in- 
vestigated in several modifications of the typic one, which exists at Seaside 
Park, N. J. The lower beach is limited by the reach of the higher tides and 
is marked by the constant shifting and grinding of the particles of sand against 
each other by wave action. The middle beach, where driftwood collects, 
supports a considerable number of herbaceous annuals, which show in a 
striking way their adaptation to unpropitious surroundings. The'most abundant 
plant of the middle beach in all the localities studied is Cakile americana 
(= C. edentula). Associated with this succulent is also another, Arenaria 
peploides, which grow in clumps, and is of a dark-green color with thick, 
fleshy leaves. It forms the so-called annual dunes which are piled up around 
its succulent stems, remaining as small hillocks of sand, through which this 
plant protrudes, until autumn, when upon the death of the sand-binder the 
sand is again caught up by the wind and carried away. Cakzdle is also in- 
strumental in catching the sand and holding it in the form of embryonic dunes. 
These two plants are the only ones found commonly on Barnegat Beach at 
Sea Side Park. 
At South Atlantic City, in addition to Cakile and Arenaria which are also 
found there, grow Salsola kali, Euphorbia polygonifolia and Cenchrus tribu- 
loides. Salsola is extremely xerophytic with succulent stem and leaves and 
spinous habit. Euphorbia, a prostrate herb, possesses latex, which is probably 
instrumental in reducing transpiration. Cenchrus, of annual habit, depends 
upon its prickly fruit for its distribution. It is abundant, as a character plant, 
at South Atlantic City, along the dune faces in the strip of succulents, and 
also as a component of the flora in the strips more distinctly removed from 
the ocean front. This is true of this grass both at Ocean City and Wildwood, 
where it is not conspicuous by its presence on the middle beach. 
The most interesting distribution of plants is met at Wildwood. Here 
the beach is extremely flat and very wide, trending to the northeast, where 
apparently it is widest. The lower beach consists of sand, packing well 
together, and when wet presenting a hard, firm, floor-like surface. Just above 
the ordinary limit of high tide are little hummocks of sand held in place by 
the stalks of grasses and other herbaceous plants which have been washed 
up by tidal action. This area of loose sand is succeeded by a lineof more 
elevated sand bordering a tidal depression inside it. Upon this low ridge of 
