9i 
The Shingle Beach as a Plant Habitat. 
(diagrammatically illustrated in Text-fig. 8). Across the proximal 
ends of many of the hooks of the Blakeney “ Marams ” a low talus 
of mobile shingle is present, and pari passu with its advance the 
plant succession becomes retrogressive, in the sense that many of 
the plants of the dormant hook are unable to colonise the new 
(mobile) surface, whilst others belonging to the pioneer vegetation 
of the main bank reappear. 
SEA 
Fig. 8. To illustrate “ hook-sliding.” The heavy outline represents the 
present position of a bank with three hooks. No. 3 is terminal, Nos. 2 and 1 
lateral in position. The former positions of main spit and the proximal parts 
of the hooks are indicated by the thin outline. The dots show the distribution 
of Suceda fruticosa. 
Among the plants common to the main bank and hooks at 
Blakeney is Suceda fruticosa (PI. 4, fig. 3). On the main hank this 
plant establishes itself from drift-borne seed in great numbers on 
the inner fringe of shingle bordering the salt-marshes. As it 
tolerates the heaping up of shingle over its roots this plant tends to 
survive the advance of the shingle and to remain growing at various 
heights on the bank in positions to which it has ascended much as 
do Psamma or Salix under analogous conditions on a wandering 
sand-dune. Thus we find Suceda fruticosa both on the fringe (the 
place of establishment) and on the body of the main bank. On the 
hooks this plant clothes the slopes on both sides but is absent from 
the top. At the place of junction of hook and main bank the fringe 
of Suaeda is of course interrupted along the latter (Text-fig. 8; 
Suaeda plants represented by dots). 
If now, as indicated by the evidence, the main bank is creeping 
landwards over marshes and hooks alike, it is to be expected that 
the distribution of the Suaedas on the main bank will be in conformity 
with the two sources from which they are derived, i.e. (1) the plants 
that establish themselves on the fringe, (2) those on the flanks of 
the hooks. Careful inspection of the ground shows that this 
