/\\ II Y app. 
61 
SKETCHES OF VEGETATION AT HOME AND ABROAD. 
IV.—Wicken Fen. 
Bv R. H. Yapp, M.A., 
[Plate IV. and Text-Figs. 9-15.] 
Professor of Botany in the University College of Wales, Aberystwyth. 
Introductory. 
HE following sketch has been written, partly on account of the 
_L general interest which centres in the vegetation of the now, 
for the most part, drained “ Fenland ” ; and partly as an introduction 
to more detailed studies, dealing with certain problems connected 
with marsh vegetation. As the work has been hitherto carried out 
chiefly at Wicken Fen, 1 the present preliminary sketch will deal 
mainly with this limited part of the Fen area. 
The Fens of the East of England form a great plain, the 
largest in Britain, comprising some 1,300 square miles of practically 
level country. In reality the Fenland is a complex delta, formed by 
what are now the Witham, the Welland, the Nene and the Great 
Ouse; just as a large portion of the Western Netherlands, on the 
other side of the North Sea, has been formed as the delta of the 
Rhine, the Maas and the Scheld. 
According to Skertchly, the Wash was once a great bay—co¬ 
extensive with the Fenland itself 3 —which occupied a basin hollowed 
out in the Jurassic clays. 3 It would seem improbable, however, 
that the Wash ever extended quite to the southern part of the area, 
where the deposits consist almost exclusively of pure peat 4 (cf. Text- 
fig. 9). 
This great shallow bay has been gradually silting up since 
post-glacial times. 5 The silted up portion has formed the northern 
Fens, whilst the present Wash, the shrunken remnant of the bay, is 
still becoming smaller year by year, through the continuance of the 
silting process. The floor of the Fenland basin “ is probably not a 
very even surface, but silt deposited by the sea, mud brought down 
by the rivers, and vegetation growing upon the surface have built 
1 By the kind permission of G. H. Verrall, Esq. 
2 Miller & Skertchly, The Fenland, Wisbech, 1878, p. 224. 
3 Ibid. p. 497. 
4 Reed, Geology of Cambridgeshire, 1897, p. 222, says, “ The 
southern limit of the silt marks the shore of the great bay— 
the predecessor of the Wash : but owing to the frequent 
invasions of the sea into the flat peat-country this line is 
complicated and indefinite.” 
‘ Miller & Skertchly, l.c p. 575. 
