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 names imply. The true lilies
are among the oldest of plants. But "water-lilies" are not lilies. They
have been placed in order between the barberry and the poppy, because the
seed-head of a water-lily is like the poppy fruit. The villarsia, which
looks like a water-lily, is not related at all, while the buck-bean is not
a bean, but akin to the gentians. Water-violet might be more properly
called water-primrose, for it is closely related to the primrose, though
its colour is certainly violet, and not pale yellow. By this time all the
bladderworts have disappeared under water. In June in a pool near the
inflow of the Thames at Day's Lock, opposite Dorchester, the fine leafless
yellow spikes of flower were standing out of the water like orchids, while
the bladders with their trapdoors were employed in catching and devouring
small tadpoles. There is something quietly horrible about these
carnivorous plants. Their bladders are far too small to take one in whole,
but catch the unhappy infant tadpoles by their tails and hold them till
they die from exhaustion.

The bank flora of the Thames is nearly all the same from Oxford to Hampton
Court, made up of some score of very fine and striking flowers that grow
from foot to crest on the wall of light marl that forms the bank.
Constantly refreshed by the adjacent water, they flower and seed, seed and
flower, and are haunted by bees and butterflies till the November frosts.