is new and suggestive of strange activities. Everything will be quiet and
motionless at first, for water beasts are very suspicious of movement
above them, and all sham dead, or lie quite still, and are strangely
invisible. On the other hand, they have none of the power of remaining
motionless for half-an-hour like land animals. Soon what look like sticks,
but are caddis larva, begin to creep on the bottom. Then more brown
objects, larvae of dragon-flies and water-beetles, detach themselves from
the stems of the plants and cruise up and down seeking what they may
devour. Other creatures feeding and swimming among or beneath the plants
crawl out on to the upper surface, and the water-beetles come up to
breathe, or to play upon the surface. One of the largest of these is a
very fine _black_ beetle, a vegetable-feeding creature. It is most
interesting to see two of them--they generally live in pairs--browsing on
one of the fern-like plants of the Thames. This plant has leaves like fern
blades, each having in turn its own small spikelets. The big beetles work
along the leaf like a cow in a cabbage yard, biting off, chewing, and
swallowing each in succession, and leaving the stem perfectly bare.
Sometimes it looks as if the two beetles were eating for a match, like the
beef-eating contests held in country public-houses, in which the winner
once boasted that he won easily "afore he came to vinegar."

The number of carnivorous creatures found in the water seems out of all
proportion to the usual order of Nature. But this is perhaps because the
minute, almost invisible creatures, or entomostraca, of which the rivers
and ponds are full, and which are the main food of the smaller water
carnivora, live mainly on decaying vegetable substance, which is
practically converted and condensed into microscopical animals before
these become in turn the food of others. It is as if all trees and grass
on land were first eaten by locusts or white ants, and the locusts and
white ants were then eaten by semi-carnivorous cows and sheep, which were