from pure water frequently changed; yet they must draw some
support from animalcula, and other nourishment supplied by the
water; because, though they seem to eat nothing, yet the
consequences of eating often drop from them. That they are best
pleased with such jejune diet may easily be confuted, since if you
toss them crumbs, they will seize them with great readiness, not to
say greediness: however, bread should be given sparingly, lest,
turning sour, it corrupt the water. They will also feed on the water-
plant called lemna (duck's meat), and also on small fry.

When they want to move a little they gently protrude themselves
with their pinnae pectorales; but it is with their strong muscular
tails only that they and all fishes shoot along with such
inconceivable rapidity. It has been said that the eyes of fishes are
immoveable: but these apparently turn them forward or backward
in their sockets as their occasions require. They take little notice of
a lighted candle, though applied close to their heads, but flounce
and seem much frightened by a sudden stroke of the hand against
the support whereon the bowl is hung; especially when they have
been motionless, and are perhaps asleep. As fishes have no eyelids,
it is not easy to discern when they are sleeping or not, because their
eyes are always open.

Nothing can be more amusing than a glass bowl containing such
fishes: the double refractions of the glass and water represent them,
when moving, in a shifting and changeable variety of dimensions,
shades, and colours; while the two mediums, assisted by the
concavo-convex shape of the vessel, magnify and distort them
vastly; not to mention that the introduction of another element and
its inhabitants into our parlours engages the fancy in a very