720 
BLAKENEY POINT IN 1913. 
survey within the next eighteen months as a companion booklet 
to our Publication No. 7, which deals with the phanerogamic 
flora. The conspicuous Algse include green forms such as 
V aucheria Thureti, Rhizoclonium, and Enteromorpha, brown 
Algae such as Fucus vesiculosus, F. volubilis, Pelvetia canali- 
culata and its remarkable free-growing form libera — a feature 
of the younger Salicornia marshes; whilst among a number of 
blue-green Algae the mud-loving Microcoleus chthonoplastes 
deserves special mention. These and other Algae occupy their 
OAvn particular zones on the protected tidal shores of the estuary, 
and play an important part in preparing the ground for the 
phanerogamic halophytes which follow in their wake. In 
addition to their systematic, distributional and biological 
features, the part which these lowly organisms play in the 
accretion of soil and building up of land is receiving attention, 
and promises to lead to interesting results. These plants have 
played and are still playing an important role on the flats near 
the Hood, where the ground level is rapidly rising. Neither 
have the Diatoms been forgotten, nor the Bacteria of the mud 
flats and marshes. Before leaving the group of the Algse it 
may interest some to hear that the curious Pelvetia can aliculat a 
forma libera was first found at Blakeney Point. (See Publi- 
cation No. 3.) Last autumn its occurrence was reported on 
the Burnham Overy marshes by Mr. Patrick Disney, and it is 
to be expected that it will be found at other points on these 
shores where appropriate conditions prevail. 
The study of algal distribution shews that this is influenced 
in an important way by the tides. In this connection it is 
hoped to instal quite shortly a recording gauge, so that full 
information may be available as to the duration of immersion 
of the plants at various levels of the tidal zone. 
The Lichens which settle on the dormant shingle have been 
under study for the last two years ; their distribution has been 
worked out, their forms identified and their manner of settle- 
ment and rate of growth investigated, a. preliminary account 
of the results in this field will shortly appear. 
