284 THE ESSEX NATURALIST.
To sum up, it would appear from the above evidence :
1. That the river-walls owe their initial formation to the
continuous subsidence of the land, which, by the
6th century a.d., had begun to threaten the meadows
bordering the Thames with serious inundation;
2. That the walls required periodical repair or heightening
during the succeeding centuries;
3. That from time to time additional innings of marshland
by "counter-walls" were effected ;
4. And that the latest recorded instance of any extensive
inning was the reclamation of Canvey Island by Jooz
Croppenburg in a.d. 1621.
SOME ESSEX PLANTS OBSERVED IN 1944.
BY J. A. WHELLAN, B.Sc.
DURING temporary residence in Essex in 1944 I did a
certain amount of field botany, some of the results
of which are set out below. All the plants have, I think,
been recorded from the County before. Many, however, are
from new localities and some of the localities, followed by (G),
are of interest, in that they confirm the records in Gibson's.
Flora of Essex. Perhaps the most striking of these is
Coriandrum sativum L., known at Coggeshall to Ray. This is
usually a mere casual, but here perhaps it has a more permanent
status.
Although the general flora has probably altered little since
Gibson's time some plants, I fear, have disappeared. The
causes are probably primarily better drainage, ploughing up of
commons, etc., "cleaner" methods of cultivation. Among
plants for which I searched carefully in Gibson's localities and
failed to find I may mention Pulicaria vulgaris Gaertn. Galley-
wood Common, Tiptree Heath, Langham Moor ; Arnoseris
minima (L) Schw, and Koerte, Lawford Mill Wood ; Lactuca
saligna L. Between Maldon and Mundon : Polygonum minus
Huds. Galleywood Common ; and Festuca Myurus L. Tiptree
Heath.
I have included neither the commonest plants nor well-
known rarities in the list. The plants are arranged in accordance
with Druce's British Plant List Ed. 2 and the vice-counties
distinguished as 18 and 19. I must here thank Messrs. J. E.