The Bouche d' Erquy in 1907. 
249 
not a few of the typical “stations” that have been charted from 
year to year shew a change of type pointing to a definite succession 
or development in the vegetation-covering. 
Nowhere on the marsh has the advance been more striking than 
in its lower part, where the vegetation abuts on the bare shifting 
sands. The long spit of marsh which stretches along in the direction 
of the mouth and lies between the main river-channel and the sand- 
dunes on the N.E. side affords an admirable example (cf. Fig. 15). 
The main body of this marsh-spit is composed of hummocky ground, 
bearing Saliconiia radicans and Obione portulacoides in profusion, 
together with a scattering of Glycerin niaritima, Sneed a maritima , 
and other halophytes on its more settled portions. This marsh-spit 
is accompanied along the whole stretch of its duneward flank by a 
broad sandy belt, often 50 or more feet across, of dwarf plants which 
are doubtless a peculiar form of Saliconiia radicans (A—A, Fig. 15), 
whilst its other flank (directed towards the main channel) is bordered 
by a corresponding zone of the form of Saliconiia herbacea which is 
sometimes distinguished as S. ramosissima (the hatching B —B, 
Fig. 15). This however is rooted in mud or muddy sand, black in 
colour. 
Taking first the 5. radicans zone on the duneward flank. This 
consists of little prostrate plants, sparsely scattered at the rate of 
about one per square yard. These plants, though indistinguishable 
from S. radicans in its first year, have the peculiarity of behaving 
as annuals, and, although they flower regularly, have been observed 
on several occasions to decay without ripening seed 1 . Evidently 
they are the pioneers of the phanerogamic vegetation and under 
their influence the sand is being gradually fixed. Our data prove that 
at many places along this zone extensive groups of permanent plants 
of S. radicans have arisen, doubtless by the survival of the dwarf 
annual variety in favoured places. In this way several acres of 
ground have acquired during the last few years a permanent 
covering of tussocks of S. radicans which quickly accrete sand- 
hummocks and grow with luxuriance. These promoted plants are 
quickly joined by Obione and later by Glyceria. The secondary 
phases of colonisation, however, are less strikingly shewn here than 
in other regions of the marsh, to be alluded to below. At present 
the conditions favour the primary phase, whilst secondary 
colonisation and consolidation appear to be in relative suspense. 
On the side towards the channel (B—B, Fig. 15) the belt 
1 This year, however, they are seeding copiously. 
