n his _Beagle_ voyage Darwin observed that vast numbers
of small gossamer spiders were borne on to the ship when it was sixty
miles distant from the land.

[Illustration: THE AUSTRALIAN FRILLED LIZARD, WHICH IS AT PRESENT TRYING
TO BECOME A BIPED

When it gets up on its hind-legs and runs for a short distance it folds
its big collar round its neck.]

[Illustration: A CARPET OF GOSSAMER

The silken threads used by thousands of gossamer spiders in their
migrations are here seen entangled in the grass, forming what is called
a shower of gossamer. At the edge of the grass the gossamer forms a
curtain, floating out and looking extraordinarily like waves breaking on
a seashore.]

[Illustration: THE WATER-SPIDER

The spider is seen just leaving its diving-bell to ascend to the surface
to capture air.

The spider jerks its body and legs out at the surface and then dives--

--carrying with it what looks like a silvery air-bubble--air entangled
in the hair.

The spider reaches its air-dome. Note how the touch of its legs indents
the inflated balloon.

Running down the side of the nest, the spider

--brushes off the air at the entrance, and the bubble ascends into the
silken balloon.

_Photos: J. J. Ward, F.E.S._]

New Devices

It is impossible, we must admit, to fix dates, except in a few cases,
relatively recent; but there is a smack of modernity in some striking
devices which we can observe in operation to-day. Thus no one will
dispute the statement that spiders are thoroughly terrestrial animals
breathing dry air, but we have the fact of the water-spider conquering
the under-water world. There are a few spiders about the seashore, and a
few that can survive douching with freshwater, but the particular case
of the true water-spider, _Argyroneta natans_, stands by itself because
the creature, as regards the female at least, has _conquered_ the
sub-aquatic environment. A flattish web is woven, somehow, underneath
the water, and pegged down by threads of silk. Along a special vertical
line the mother spider ascends to the surface and descends again, having
entangled air in the hairs of her body. She brushes off this air
underneath her web, which is thereby buoyed up into a sort of dome. She
does this over and over again, never getting wet all the time, until the
domed web has become like a diving-bell, full of dry air. In this
eloquent anticipation of man's rational device, this creature--far from
being endow