the hog's bristle, which continues to invest the
polype. When it reaches the worm, which holds the mouth open, it
either pushes the worm or passes by its side, and at last comes out by
the mouth, the polype being thus completely turned inside out."

[Illustration: HYDRA, WITH YOUNG ONES BUDDING OUT FROM ITS SIDE.]

Very strange, indeed, to think that animals with the wrong side
outermost should continue to eat, grow, and multiply, as Trembley
assures us his specimens did, though, perhaps, we shall not wonder
that they often tried to turn themselves back to their original
condition, and with success, unless Trembley took steps to prevent
them. There are other strange things recorded of the fresh-water
polypes, as that different individuals can be grafted together without
the slightest inconvenience to any of the parties, the joint-stock
company of course being limited.

The hydrae live on small worms, larvae of gnats, water-fleas, and other
minute creatures; they catch them with their tentacles or
fishing-lines, and draw them to the mouth. It is maintained by many
observers, with good reason, that these arms have the power of
paralysing, in an instant, the worms they wrap themselves round. There
are at least three well-marked species of hydrae to be met with in the
ponds and ditches of this country. There is the green hydra, the
light flesh-coloured or common hydra, and the long-armed hydra, the
most interesting of all. See, there is the water-primrose, now in
flower, with its delicate pink corolla and bright orange centre. Let
us gather a few plants, and then return home.

[Illustration]

FOOTNOTES:

[Footnote B: 'Marvels of Pond Life,' by H. J. Slack, p. 92.]

WALK V.

MAY.

To-day we will go to Shawbury and try our luck with the trout. If the
fish will not rise there will be plenty to observe, and I have no
doubt we shall enjoy the day thoroughly; the wind is in the south-west
and the day is cloudy; the May-fly is well out, and I think we have
every chance of good sport. Let us look out our fishing-tackle and
drive off at once to the river. How delightful it is to stroll by the
river side and hear the rippling of the water; delightful, too, is the
sensation of feeling at the end of your line the tugs and jumps of a
good lively trout. I cannot resist quoting some lines from 'The
Angler's Song,' which I think you will say are very pretty:

Merry in the greenwood is the note of horn and hound,
A