ts, usually less striking, are known in many
birds; but the most signal illustration is that of the kea or Nestor
parrot of New Zealand, which has taken to lighting on the loins of the
sheep, tearing away the fleece, cutting at the skin, and gouging out
fat. Now the parrot belongs to a vegetarian or frugivorous stock, and
this change of diet in the relatively short time since sheep-ranches
were established in New Zealand is very striking. Here, since we know
the dates, we may speak of evolution going on under our eyes. It must be
remembered that variations in habit may give an animal a new
opportunity to test variations in structure which arise mysteriously
from within, as expressions of germinal changefulness rather than as
imprints from without. For of the transmissibility of the latter there
is little secure evidence.

Experiments in Locomotion

It is very interesting to think of the numerous types of locomotion
which animals have discovered--pulling and punting, sculling and rowing,
and of the changes that are rung on these four main methods. How
striking is the case of the frilled lizard (Chlamydosaurus) of
Australia, which at the present time is, as it were, experimenting in
bipedal progression--always a rather eventful thing to do. It gets up on
its hind-legs and runs totteringly for a few feet, just like a baby
learning to walk.

How beautiful is the adventure which has led our dipper or
water-ouzel--a bird allied to the wrens--to try walking and flying under
water! How admirable is the volplaning of numerous parachutists--"flying
fish," "flying frog," "flying dragon," "flying phalanger," "flying
squirrel," and more besides, which take great leaps through the air. For
are these not the splendid failures that might have succeeded in
starting new modes of flight?

Most daring of all, perhaps, are the aerial journeys undertaken by many
small spiders. On a breezy morning, especially in the autumn, they mount
on gate-posts and palings and herbage, and, standing with their head to
the wind, pay out three or four long threads of silk. When the wind tugs
at these threads, the spinners let go, and are borne, usually back
downwards, on the wings of the wind from one parish to another. It is
said that if the wind falls they can unfurl more sail, or furl if it
rises. In any case, these wingless creatures make aerial journeys. When
tens of thousands of the used threads sink to earth, there is a "shower
of gossamer." O