92 
F. W. Oliver. 
probability is realised on the “ Marams ” at Blakeney, for in several 
cases those parts of the main bank which are in alignment with 
the proximal segments of the hooks are free from Suaedas except 
for a double row (corresponding with the flanking rows of the hooks) 
running obliquely up the hank (Text-fig. 8). On other parts of the 
main bank no such restriction in the distribution of the Suseda is 
found to occur. 1 
In view of these results, inferred from the vegetation, it seems 
likely that the hooks on the “ Marams” were formerly considerably 
longer than is now the case. The main bank is slowly creeping 
over them, and their proximal ends have doubtless long ago emerged 
on the sea face and been disintegrated by the waves—an inference 
susceptible of corroboration by a direct search for old surfaces by 
probing or digging. This bit of vanished history is reconstructed 
in Text-fig. 8 ; former contours being sketched in thin lines. 
The phenomena associated with “ hook-sliding ” have a general 
as well as a merely particular interest connected with the history 
of the Blakeney Bank. They serve to emphasize the importance 
of the historic treatment of a vegetation—of the detailed study of 
the ontogeny and “ succession ” of a vegetation in determining the 
status of its component elements. 
The Various Types of Habitat. 
It will have been gathered from the preceding account that a 
shingle spit should show a considerable diversity of plant habitats in 
respect of both exposure and mobility; an expectation at once 
confirmed when the ground is inspected—not only in respect of the 
two factors named, but also in the nature of the soil which 
occupies the interstices of the coarser materials. 
First, the principal topographical regions must be enumerated 
and provisional names allotted for convenience of reference. 
The primary regions will include (1) the main bank, and (2) 
1 The tenacity with which Stueda fruticosa holds its own on the 
Blakeney Bank regardless of the mobility of the shingle is 
certainly worthy of record. Under the milder climatic 
conditions of the Chesil Bank this plant is restricted to the 
terrace and appears to be incapable of rising more than two 
feet at the outside when the shingle collects above it. At 
Blakeney, on the other hand, Suseda is found all over the 
bank, persisting even to the crest, seven feet above spring 
tide high-water-mark, and occasionally in isolated specimens 
a little distance down the sea face. This difference in behaviour 
at the two localities is hardly to be explained on climatic 
grounds—more probably it is determined by the composition 
of the soil. 
