The Naturalist on the Thames | Page 7

and fish, unfrightened by the boat traffic, are tamer and more
visible.
[Illustration: A FLOWERY BANK NEAR COOKHAM. _From a
photograph by E. Seeley_.]
The things in the waters and growing out of the waters are very, very
old. The mountains have been burnt with fire; lava grown solid has
turned to earth again and grows vines; chalk was once sea-shells; but
the clouds and the rivers have altered not their substance. Also, so far
as this planet goes, many of the water plants are world-encircling,
growing just as they do here in the rivers of Siberia, in China, in
Canada, and almost up to the Arctic Circle. The creatures which lived
on these prehistoric plants live on them now, and in exactly the same
parts of the stream. The same shells lie next the banks in the shallows
as lie next the bank of the prehistoric river of two million years ago
whose bed is cut through at Hordwell Cliffs on the Solent. The same
shells lie next them in the deeper water, and the sedges and rushes are
as "prehistoric" as any plant can well be. In the clay at Hordwell, which
was once the mud of the river, lie sedges, pressed and dried as if in the
leaves of a book, almost exactly similar in colour, which is kept, and in
shape, which is uninjured, to those which fringe the banks of the
Thames to-day. These fresh-water plants show their hoary antiquity by
the fashion of their generation. Most of them are
mono-cotyledonous--with a single seed-lobe, like those of the early
world. There is nothing quite as old among the Thames fishes as the
mud fishes, the lineal descendants of the earliest of their race. But the
same water creatures were feeding on the same plants perhaps when the
Thames first flowed as a river.
[Illustration: BURR REED AND FLOWERING RUSH. _From

photographs by E. Seeley._]
The sedge fringe in the shallows, the "haunt of coot and tern" elsewhere,
and of hosts of moorhens and dabchicks on the now protected river, is
mainly composed of the giant rush, smooth and round, which the
water-rats cut down and peel to eat the pith. These great rushes,
sometimes ten feet high, die every year like the sickliest flowers, and
break and are washed away. Few people have ever tried to reckon the
number of kinds of sedges and reeds by the river, and it would be
difficult to do so. There are forty-six kinds of sedge (_carex_), or if the
Scirpus tribe be added, sixty-one, found in our islands. They are not all
water plants, for the sand-sedge with its creeping roots grows on the
sandhills, and some of the rarest are found on mountain-tops. But the
river sedges and grasses, with long creeping roots of the same kind,
have played a great part in the making of flat meadows and in the
reclamation of marshes, stopping the water-borne mud as the
sand-sedge stops the blowing sand. They have done much in this way
on the Upper Thames, though not on the lower reaches of the river. The
"sweet sedge," so called--the smell is rather sickly to most tastes--is
now found on the Thames near Dorchester, and between Kingston and
Teddington among other places, though it was once thought only to
flourish on the Norfolk and Fen rivers. It is not a sedge at all, but
related to the common arum, and its flower, like the top joints of the
little finger, represents the "lords and ladies" of the hedges. So the burr
reed, among the prettiest of all the upright plants growing out of the
water, is not a reed, but a reed mace. Its bright green stems and leaves,
and spiky balls, are found in every suitable river from Berkshire to the
Amur, and in North America almost to the Arctic Circle. In the same
way the yellow water villarsia, which though formerly only common
near Oxford, has greatly increased on the Thames until its yellow stars
are found as low as the Cardinal's Well at Hampton Court, extends
across the rivers of Europe and Asia as far as China. The cosmopolitan
ways of these water plants are easily explained. They live almost
outside competition. They have not to take their chance with every new
comer, for ninety-nine out of a hundred stranger seeds are quietly
drowned in the embosoming stream. The water itself keeps its
temperature steadily, and only changes slowly and in no great degree,
and then, when the plants are in their winter sleep the stream may well

say that "men may come and men may go, but I go on for ever." The
same is very largely true of the things which live in the brook.
Many of the flowers are not quite what their